大写字母标号转为数值

如“A”表示1；“AB"表示（27+2）；、、、、、、

#include "string.h"

#include "stdio.h"

#include "stdlib.h"

#include "math.h"

int char_to_num(char *c)

{

char *ch;

int num=0;

int p=0;

int length=(int)strlen(c);

ch=c;

for(int i=0;i<length;i++)

{

p=ch[length-1-i];

p=p-'A'+1;

num= num + (int)pow ((double)27,i) * p;

}

return num;

}

int main()

{

char *string;

int num=0;

string =(char*) malloc(100*sizeof(char));

if(string==NULL)

{

printf("error");

return 0;

}

scanf("%s",string);

num = char_to_num(string);

printf("%s changes to number is %d",string,num);

free(string);

return 0;

}