#include <stdio.h> void sum (int a,int b) { int count = 0;//计数器 int sum = 0,i,t,j; for(i = a;i<=b;i++) { t = i; sum = t%10;//让sum 等于t的个位 for(j = 0;t>0;j++) { t = t/10; sum = sum + t%10; } if (sum % 5 == 0) { count++; } } printf("%d\n",count); } int main() { int a,b; scanf("%d%d",&a,&b); sum(a,b); return 0; }