C语言版本

#include <stdio.h>
#include <stdbool.h>

int main() {
    char S[201];
    char T[201];
    scanf("%s", S);
    scanf("%s", T);
    bool flagS[26] = {false};
    for (int i = 0; i < strlen(S); i++) {
        flagS[S[i]-'a'] = true;
    }
    bool flagT[26] = {false};
    for (int i = 0; i < strlen(T); i++) {
        flagT[T[i]-'a'] = true;
    }
    bool flag = true;
    for (int i = 0; i < 26; i++) {
        if (flagS[i] == true) {
            if (flagT[i] != true) {
                flag = false;
                break;
            }
        }
    }
    if (flag) {
        printf("true\n");
    } else {
        printf("false\n");
    }
    return 0;
}

Python版本

while True:
    try:
        S, T = input(), input()
        if set(S) & set(T) == set(S):
            print('true')
        else:
            print('false')
    except:
        break