国际C语言乱码大赛(IOCCC)经典之作

你也许听说过“国际C 语言乱码大赛（IOCCC ）”，能获奖的人毫无疑问是世界顶级C

程序员。这是他们利用C 语言的特点极限挖掘的结果。下面这个例子就是网上广为流传的

一个经典作品：// 原始代码如下

#include <stdio.h>

char *a;main(int t,int _,char* a){return!0<t?t<3?main(-79,-13,a+main(-87,1-_,

main(-86,0,a+1)+a)):1,t<_?main(t+1,_,a):3,main(-94,-27+t,a)&&t==2?_<13?

main(2,_+1,"%s %d %d\n"):9:16:t<0?t<-72?main(_,t,

"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/")

:t<-50?_==*a?putchar(31[a]):main(-65,_,a+1):main((*a=='/')+t,_,a+1)

:0<t?main(2,2,"%s"):*a=='/'||main(0,main(-61,*a,

"!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:\nuwloca-O;m .vpbks,fxntdCeghiry"),a+1);}

这是IOCCC 1988 年获奖作品，作者是Ian Phillipps。

毫无疑问，Ian Phillipps 是世界上最顶级的C 语言程序员之一。你可以数数这里面用了多少个符号。当然这里我并不会讨论这段代码，也并不是鼓励你也去写这样的代码（关于这段代码的分析，你可以上网查询）。恰恰相反，我要告诉你的是： 大师把代码写成这样是经典，你把代码写成这样是垃圾！

所以在垃圾和经典之间，你需要做一个抉择。

// 把代码格式化一下

#include <stdio.h>

char *a; // can be omitted due to function field

main(int t,int _,char* a){

return !0<t ?

t<3 ?

main(-79,-13,a+main(-87,1-_,main(-86,0,a+1)+a))

:1

, t<_ ?

main(t+1,_,a)

:3

, main(-94,-27+t,a)&&t==2 ?

_<13 ?

main(2,_+1,"%s %d %d\n")

:9

:16

:t<0 ?

t<-72 ?

main(_,t,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/")

:t<-50 ?

_==*a ?

putchar(31[a])

:main(-65,_,a+1)

:main((*a=='/')+t,_,a+1)

:0<t ?

main(2,2,"%s")

:*a=='/'||main(0,main(-61,*a,"!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:\nuwloca-O;m .vpbks,fxntdCeghiry"),a+1)

;

}

// 翻译成常规语言

// condition ? true : false ; a,b,c generate step

#include <stdio.h>

main(int t,int _,char* a){

// 逻辑运算优先级，便于理解

if(!0<t){

if(t<3)

main(-79,-13,a+main(-87,1-_,main(-86,0,a+1)+a));

else

1;

if(t<_)

main(t+1,_,a);

else

3;

if(main(-94,-27+t,a)&&t==2){

if(_<13)

return main(2,_+1,"%s %d %d\n");

else

return 9;

}else

return 16;

}else{

if(t<0){

if(t<-72){

return main(_,t,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

}else{

if(t<-50){

if(_==*a)

return putchar(31[a]); // pointer compile a[b] with b[a]

else

return main(-65,_,a+1);

}else{

return main((*a=='/')+t,_,a+1);

}

}

}else{

if(0<t)

return main(2,2,"%s");

else

// condition compile step a||b

return *a=='/'||

main(0,main(-61,*a,"!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:\nuwloca-O;m .vpbks,fxntdCeghiry"),a+1);

}

}

}

// 除去不需要的，重构if语句

#include <stdio.h>

main(int t,int _,char* a){

if(1<t){

if(t<3)

main(-79,-13,a+main(-87,1-_,main(-86,0,a+1)+a));

if(t<_)

main(t+1,_,a);

if(main(-94,-27+t,a)&&t==2){

if(_<13)

return main(2,_+1,"%s %d %d\n");

else

return 9;

}else

return 16;

}else if(t<0){ // 根据语义，可进一步重构

if(t<-72){

return main(_,t,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

}else if(t<-50){

if(_==*a)

return putchar(a[31]); // 指针编译原理a[b]和b[a]，注意是char*

else

return main(-65,_,a+1);

}else{

return main((*a=='/')+t,_,a+1);

}

}else if(0<t){

return main(2,2,"%s");

}else{

if(!(*a=='/'))

return main(0,main(-61,*a,"!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:\nuwloca-O;m .vpbks,fxntdCeghiry"),a+1);

else

return 1; // 等于(*a=='/')

}

}
// 编译环境main入口，CRTO.C for main(__argc, __argv, _environ);

// 方法的编译原来，返回值的寄存器状态

// 变量的类型转换reinterpret_cast

// 使用一个新的main方法，将旧的用一个新方法'decode'表示

// 根据题设，本程序执行方式为无命令参数，即，argc==1

// 变量的声名规约，改变变量名以方便理解

// 进一步重构if语句

#include <stdio.h>

int decode(int arg1,int arg2,char* sCodec){

if(1<arg1){

if(arg1<3)

decode(-79,-13,sCodec+decode(-87,1-arg2,decode(-86,0,sCodec+1)+sCodec));

if(arg1<arg2)

decode(arg1+1,arg2,sCodec);

if(decode(-94,-27+arg1,sCodec)&&arg1==2){

// 内部递归，无后续分支，可展平为递推方式

if(arg2<13)

return decode(2,arg2+1,"%s %d %d\n");

else

return 9;

}else

return 16;

}else if(arg1<-72){

// 可根据arg1范围代入。本条件代入后略

return decode(arg2,arg1,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

}else if(arg1<-50){

// 内部递归，无后续分支，可展平为递推方式

if(arg2==*sCodec)

return putchar(sCodec[31]);

else

return decode(-65,arg2,sCodec+1);

}else if(arg1<0){

// 内部递归，无后续分支，可展平为递推方式

return decode((*sCodec=='/')+arg1,arg2,sCodec+1);

}else if(0<arg1){ // arg1 == 1，初始情况，根据arg1取值取舍

return decode(2,2,"%s");

}else{ // arg1 == 0

if(!(*sCodec=='/'))

// 内部递归，无后续分支，可展平为递推方式

return decode(0,decode(-61,*sCodec,"!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:\nuwloca-O;m .vpbks,fxntdCeghiry"),sCodec+1);

else

return 1;

}

}

int main(int argc, char* argv[], char** _environ){

return decode(argc,(int)argv,(char*)_environ);

}

// 分析出递归顶层返回值。

// 注意所有return的含义，9/16/1/putchar()，Non Zero -> TRUE

// 分析arg1的内容，重构方法，有些坳，自己试着理解吧

#include <stdio.h>

int decode(int arg1,int arg2,char* sCodec){

if(1<arg1){

if(arg1<3){

decode(0,-86,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

decode(1-arg2,-87,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

decode(-13,-79,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

}

if(arg1<arg2)

decode(arg1+1,arg2,sCodec);

decode(-27+arg1,-94,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

if(arg1==2){

while(arg2<13){

arg2 ++;

sCodec = "%s %d %d\n";

// 上方条件代入

if(arg1<3){

decode(0,-86,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

decode(1-arg2,-87,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

decode(-13,-79,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

}

if(arg1<arg2)

decode(arg1+1,arg2,sCodec);
decode(-27+arg1,-94,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

}

}

}else if(arg1<-50){

// 判断条件可达，取舍

char* s = sCodec;

while(!(arg2==*s)){

s ++;

}

putchar(s[31]);

}else if(arg1<0){

for(;arg1<0;arg1+=(*sCodec=='/'))

sCodec ++;

decode(0,arg2,sCodec+1); // 条件合并

}else if(arg1 == 0){

while(!(*sCodec=='/')){

// 条件合并

decode(-61,*sCodec,"!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:\nuwloca-O;m .vpbks,fxntdCeghiry");

sCodec ++;

}

}

return 1; // return TRUE only

}

int main(int argc, char* argv[], char** _environ){

decode(2,2,"%s");

return 9;

}
// 分析条件，重构2

#include <stdio.h>

int decode(int arg1,int arg2,char* sCodec){

if(1<arg1){

if(arg1<3){

// arg1 <= 0

decode(0,-86,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

decode(1-arg2,-87,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

decode(-13,-79,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

}

if(arg1<arg2)

// 1 < arg1 < 13(max arg2)

decode(arg1+1,arg2,sCodec);
// arg1 <= 0，下同

decode(-27+arg1,-94,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

if(arg1==2){

while(arg2<13){

arg2 ++;

sCodec = "%s %d %d\n";

if(arg1<3){

decode(0,-86,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

decode(1-arg2,-87,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

decode(-13,-79,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

}

if(arg1<arg2)

decode(arg1+1,arg2,sCodec);
decode(-27+arg1,-94,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/");

}

}

}else if(arg1<=0){

// 单一条件代码组

int border = (arg1<0);

for(;arg1<0;arg1+=(*sCodec=='/'))

sCodec ++;

if(border)

sCodec ++; // 边界条件，注意

while(!(*sCodec=='/')){

char* s = "!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:\nuwloca-O;m .vpbks,fxntdCeghiry";

while(!(*sCodec==*s)){

s ++;

}

putchar(s[31]);

sCodec ++;

}

}

return 1;

}

int main(int argc, char* argv[], char** _environ){

decode(2,2,"%s");

return 9;

}
// 分析arg2代码流向，重构3

// tip.arg1 in function decode always '> 1'

// the usage of arg1, arg2, sCodec. Can be omitted.

#include <stdio.h>

void decode2(int arg1){

char* sCodec = "@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/";

int border = (arg1<0);

for(;arg1<0;arg1+=(*sCodec=='/'))

sCodec ++;

if(border)

sCodec ++;

while(!(*sCodec=='/')){

char* s = "!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:\nuwloca-O;m .vpbks,fxntdCeghiry";

while(!(*sCodec==*s)){

s ++;

}

putchar(s[31]);

sCodec ++;

}

}

int decode(int arg1,int arg2){

// 考虑初始条件的 arg1 == 2, arg2 == 2，代码合并

// 内部递归，展平为递推方式，注意边界条件和递归嵌套的调用特点

if(arg1<3){

decode2(0);

decode2(1-arg2);

decode2(-13);

}

if(arg1<arg2)

decode(arg1+1,arg2);
decode2(-27+arg1);

if(arg1==2){

while(arg2<13){

arg2 ++;

if(arg1<3){

decode2(0);

decode2(1-arg2);

decode2(-13);

}

if(arg1<arg2)

decode(arg1+1,arg2);
decode2(-27+arg1);

}

}

return 1;

}

int main(int argc, char* argv[], char** _environ){

decode(2,2);

return 9;

}

// 最终结果

#include <stdio.h>

void decode2(int arg1){

char* sCodec = "@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/";

int border = (arg1<0);

for(;arg1<0;arg1+=(*sCodec=='/'))

sCodec ++;

if(border)

sCodec ++;

while(!(*sCodec=='/')){

char* s = "!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:\nuwloca-O;m .vpbks,fxntdCeghiry";

while(!(*sCodec==*s)){

s ++;

}

putchar(s[31]);

sCodec ++;

}

}

int decode(){

int arg1, arg2;

for(arg2=2;arg2<=13;arg2++){

decode2(0);

decode2(1-arg2);

decode2(-13);
for(arg1=arg2;arg1>=2;arg1--)

decode2(-27+arg1);

}

return 1;

}

int main(int argc, char* argv[], char** _environ){

decode();

return 9;

}

// 额外写段代码，看一下。对照之后推一下原始代码的结果吧。

#include <stdio.h>

int main(int argc, char* argv[], char** _environ){

char a[]="@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/";

char b[]="!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:\nuwloca-O;m .vpbks,fxntdCeghiry";

for(int i=0;i<sizeof(a);++i){

for(int j=0;j<sizeof(b);++j)

if(a[i]==b[j]){

a[i]=b[j+31];

break;

}

}

printf("%s",a);

return 1;

}