代码

#include <stdio.h>
inline unsigned g() {
unsigned t = getchar()-48;
t=t*10+ getchar()-48;
t=t*10+ getchar()-48;
return t*10+ getchar()-48;
}unsigned long long x[8500];
  
int main() {
  unsigned a[2500], b[2500];
  int i,j;unsigned k;unsigned long long cy=0;
  for(i=0;i<2500;i++)a[i]=g();getchar();
  for(i=0;i<2500;i++){
    k=g();
    for(j=0;j<2500;j++)x[i+j+1]+=(unsigned long long)a[i]*k;
  }//if(getchar()!=10)while(1)putchar('s');
  for(i=5000;i--;){cy+=x[i];x[i]=cy%10000,cy/=10000;}//while(x[0]==0);
  printf("%d",x[0]);for(i=1;i<5000;i++){
    printf("%04d",x[i]);
  }

  }

评测结果