08_05_tillzero.c

#include <stdio.h>
int main(int argc, const char * argv[]) {
    int wallet = 1000;
    int amount = 0;
    while (wallet > 0) {
        printf("amount? ");
        scanf("%d", &amount);
        wallet -= amount;
        printf("残高: %d\n", wallet);
    }
    return 0;
}