做了一小时没做出来，求解呀

复制代码到粘帖板
#include<iostream>
int main() {
    int n,mon,pre,num=0,die,flag=1;
    mon=0;
    for(n=1; n<=12; n++) {
        scanf("%d",&pre);
        mon=mon+300-pre;
        if(mon<0) {
            flag=0;
            die=n;
            break;
        } else {
            num+=mon/100;
            mon%=100;
        }
    }
    if(flag==0) {
        printf("-%d",die);
    } else  {
        mon=mon+num*120;
        printf("%d",mon);
    }
    return 0;
}

 觉得有用的话采纳一下哈

int add = 300;//新增的钱
    float sum = 0;//存的钱
    int sumb = 0;//自己手里钱
    int m = 0;//预算
    int a = 0;
    int b = 0;
    int i = 0;
    do
    {
        scanf("%d",&m);
        printf("%d\n",m);
        if(m > 0 && m < 350)
        {
            i++;//第几个月
            a = (add + sumb) - m;
            if(a < 0)
            {
                printf("\n-%d",i);
                break;
            }
            else
            {
                b = a/100 *100;
                sum += b;
                sumb = a-b;                
            }
        }
    }while(i<12);
    printf("%f",sum*1.2);