判斷字串中字元出現的頻率

#include "stdio.h"#include "stdlib.h"int main(){char a[50];gets(a);printf("%s\n",a);char re[50];int num[50];    int k=0,flag=0,j=0,i;re[0]=a[0];num[0]=1;for (i=1;a[i]!=0;i++){flag=0;for (j=0;j<=k;j++){if (re[j]==a[i]){   flag=1;   break;}}if (flag==0){re[++k]=a[i];num[k]=1;}else{num[j]++;;}}for (i=0;i<=k;i++){printf("%4c",re[i]);}printf("\n");for (i=0;i<=k;i++){printf("%4d",num[i]);}printf("\n");return 0;}