题解 | 记数问题

#include <stdio.h>
int judge (int num,int x){
    int count=0,c;
    do{
c=num%10;
if (c==x)
count++;
num/=10;
 }while (num>0);
 return count;}
 int main () {
    int n,x,i,sum=0,c;
    scanf("%d %d",&n,&x);
    for(i=1;i<=n;i++){
    c=judge(i,x);
    sum+=c;}
    printf("%d",sum);
    return 0;
 }