poj3673---双重for循环
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#include <stdio.h> #include <stdlib.h> #include <string.h> #define MAX 15 int main() { int i,j,sum=0; char s1[MAX],s2[MAX]; scanf("%s %s",s1,s2); for(i=0; i<strlen(s1); i++) { for(j=0; j<strlen(s2); j++) { sum += (s1[i] - '0') * (s2[j] - '0'); } } printf("%d\n",sum); return 0; }