NOIP 国王游戏 codevs1198 贪心+高精度

#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;
const int maxn=10000+5;
int n,tmp[maxn],a[maxn],aa[maxn],MAX[maxn],f,maxlen,len;
char str[maxn];
struct M{
int x,y,pro;
friend bool operator < (M a,M b){
if(a.pro==b.pro)
return a.y<b.y;
return a.pro<b.pro;
}
}s[maxn];
inline void mul(int a[],int b){
memset(tmp,0,sizeof(tmp));
for(int i=1;i<=len;i++)
tmp[i]=a[i]*b;
for(int i=1;i<=len;i++)
if(tmp[i]/10)
tmp[i+1]+=tmp[i]/10,tmp[i]%=10;
while(tmp[len+1])
len++;
while(tmp[len]/10)
tmp[len+1]+=tmp[len]/10,tmp[len]%=10,len++;
for(int i=1;i<=len;i++)
a[i]=tmp[i];
}
inline void div(int a[],int b){
memset(tmp,0,sizeof(tmp));
int x=0;
for(int i=1;i<=len;i++)
tmp[i]=(a[i]+x*10)/b,x=(a[i]+x*10)%b;
int pd=0;
for(int i=1;i<=len;i++)
if(tmp[i]){
pd=1;
break;
}
if(pd){
int i=1;
for(;tmp[i]==0;i++);
f=i;
for(;i<=len;i++){
if((tmp[i]>MAX[i]&&len-f+1==maxlen)||len-f+1>maxlen){
for(int j=f;j<=len;j++)
MAX[j]=tmp[j];
maxlen=len-f+1;
break;
}
if(maxlen>len-f+1||tmp[i]<MAX[i])
break;
}
}
}
signed main(void){
scanf("%d",&n);
for(int i=0;i<=n;i++)
scanf("%d%d",&s[i].x,&s[i].y),s[i].pro=s[i].x*s[i].y;
sort(s+1,s+n+1);
for(int i=0;s[0].x;i++)
str[i]=s[0].x%10+'0',s[0].x/=10;
len=strlen(str);
for(int i=1;i<=len;i++)
a[i]=str[i-1]-'0';
for(int i=1;i<=len;i++)
aa[i]=str[len-i]-'0';
for(int i=1;i<=n;i++){
div(aa,s[i].y),mul(a,s[i].x);
for(int j=1;j<=len;j++)
aa[j]=a[len-j+1];
}
for(int i=f;i<=maxlen+f-1;i++)
cout<<MAX[i];
cout<<endl;
return 0;
}