题解 | 找出字符串中第一个只出现一次的字符

#include <stdio.h>
#include <string.h>

int main() {
    char str[1000];
    scanf("%s", str);
    int arr[126] = {0}, n = 0, m;
    int len = strlen(str);
    for (int i = 0; i < len; i++) {
        m = str[i];
        arr[m]++;
    }
    for (int i = 0; i < len; i++) {
        m = str[i];
        if(arr[m] == 1){
            printf("%c", str[i]);
            n = 1;
            break;
        }
    }
    if (n == 0) {
        printf("-1");
    }
    return 0;
}