注意加上没有存进储蓄的自己手里的钱……低级错误

#include<iostream>
using namespace std;

int main()
{
    int ys,money,chux=0;
    for (int i=1;i<=12;i++)
    {
        cin>>ys;
        money=300+money-ys;
        if (money<0)
        {
        cout<<-i;
        return 0;
        }
        if (money>=100)
        {
            chux=chux+money-money%100;
            money%=100;
        }
    }
    cout<<chux*120/100+money;
    return 0;
}

#include<iostream>
using namespace std;
int a[13];
int main()
{
    int sum=0,sum2=0;
    for(int i=0;i<12;i++)
    {
        cin>>a[i];
    }
    for(int i=0;i<12;i++)
    {
        sum+=300;
        sum-=a[i];
        if(sum<0)
        {
            cout<<"-"<<i+1<<endl;
            return 0;
        }
        sum2+=sum/100*100;
        sum%=100;
    }
    cout<<sum+sum2*1.2<<endl;
    return 0;
}

#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
    double ans=0;
    int a[12]={},j,k,s=0;
    for(j=0;j<12;j++)  cin>>a[j];
    for(j=0;j<12;j++){
        s+=300;
        s-=a[j];
        if(s<0){
            j++;
            cout<<-j;
            return 0;
        }
        for(k=0;k<37;k++){
            if(s>=100){
                s-=100;
                ans+=100;
            }
            else{
                break;
            }
        }
    }
    ans*=1.2;
    cout<<ans+s;
}

这题看得我意犹未尽。。。给我3分钟都能做出来
#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
double ans=0;
int a[12]={},j,k,s=0;
for(j=0;j<12;j++) cin>>a[j];
for(j=0;j<12;j++){
s+=300;
s-=a[j];
if(s<0){
j++;
cout<<-j;
return 0;
}
for(k=0;k<37;k++){
if(s>=100){
s-=100;
ans+=100;
}
else{
break;
}
}
}
ans*=1.2;
cout<<ans+s;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
        int a[20];
        for (int i = 1; i <= 12; i++)
        {
                //存入每个月的预算
                cin >> a[i];
        }
        //sum:津津手里有的钱
        int sum = 0;
        //mum:存在妈妈那里的钱
        int mum = 0;
        for (int i = 1; i <= 12; i++)
        {
                //每月300零花钱
                sum += 300;
                if (a[i] > sum)//如果这个月钱不够
                {
                        //输出
                        cout << -i << endl;
                        return 0;
                }
                else if (sum - a[i] > 100)//如果津津剩下的钱多于100
                {
                        mum += (sum - a[i]) / 100 * 100;//存在妈妈那里
                        sum = (sum - a[i]) % 100;
                }
                else//如果剩下的钱不够100
                {
                        //直接花掉
                        sum -= a[i];
                }
        }
        //剩下的钱=津津手里的钱+妈妈手里的钱*1.2
        cout << sum + mum * 1.2 << endl;
        system("pause");
}

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cstdlib>
#include <cmath>
#define pi 3.14159265358979
#define eps 1e-10
#define TN 50002
using namespace std;
int a[101];
int ans,tt,l;
int main()
{
for(int i=1;i<=12;i++) scanf("%d",&a[i]);
for(int i=1;i<=12;i++)
{
ans+=300;
if(ans<a[i]) {printf("-%d",i);return 0;}

//if(ans-a[i]>=100)
{l=(ans-a[i])/100;ans=(ans-a[i])%100;tt+=l*100;}
}
printf("%d",120*tt/100+ans);
return 0;
}

暴力模拟就好啦~

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <iomanip>
#include <cstdlib>
using namespace std;

int a[13];
int b;
int n;

int main()
{
    for(int i=1;i<=12;i++)
        cin>>a[i];
    for(int i=1;i<=12;i++)
    {
        b+=300;
        if(b<a[i])
        {
            cout<<-i<<endl;
            return 0;
        }
        else
            b-=a[i];
        while(b>=100)
            {b-=100,n++;}
    }
    cout<<n*120+b<<endl;
    return 0;
}
     

#include<stdio.h>
int main()
{
int year[12];
int money=0;
int mom=0;
for(int i=0;i<12;i++)
{
scanf("%d",&year[i]);
}
for(int i=0;i<12;i++)
{
money+=300;
if(money>=year[i])
{
money-=year[i];
if(money>=100)
{
mom+=money-money%100;
money-=money-money%100;
}
else
{
money+=0;
}
}
else
{
printf("-%d",i+1);
return 0;
}
}
money+=(mom/100)*120;
printf("%d",money);
}

#include<bits/stdc++.h>
using namespace std;
int main(){
int n=0,cq=0;
int a[15];
for(int i=1;i<=12;i++){
cin>>a[i];
}
for(int i=1;i<=12;i++){
n+=300;
if(n<a[i]){
cout<<"-"<<i;
return 0;
}else if((n-a[i])>100){
cq+=((n-a[i])-(n-a[i])%100);
n-=((n-a[i])-(n-a[i])%100);
}
n-=a[i];
}
cout<<n+(cq*1.2);
return 0;
}

**//废话不多说，代码如下
#include<iostream>
using namespace std;
int a[13];
int main()
{
int sum=0,sum2=0;
for(int i=0;i<12;i++)
{
cin>>a[i];
}
for(int i=0;i<12;i++)
{
sum+=300;
sum-=a[i];
if(sum<0)
{
cout<<"-"<<i+1<<endl;
return 0;
}
sum2+=sum/100*100;
sum%=100;
}
cout<<sum+sum2*1.2<<endl;
return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <iostream>
using namespace std;

int main()
{
int q,w,a,b,c,d,e,f,g,h,i,j,k,l,m,n;
cin>>a>>b>>c>>d>>e>>f>>g>>h>>i>>j>>k>>l;
w=0;
w=w+300;
if(w-a>=0)
{q=(w-a-((w-a)%100));//cun ru de qian
w=w-a-(w-a-((w-a)%100));
w=w+300;
if(w-b>=0)
{

q=q+(w-b-((w-b)%100));
w=w-b-(w-b-((w-b)%100))+300;
if(w-c>=0)
{q=q+(w-c-((w-c)%100));
w=w-c-(w-c-((w-c)%100))+300;
if(w-d>=0){
q=q+(w-d-((w-d)%100));
w=w-d-(w-d-((w-d)%100))+300;
if(w-e>=0){
q=q+(w-e-((w-e)%100));
w=w-e-(w-e-((w-e)%100))+300;
if(w-f>=0)
{ q=q+(w-f-((w-f)%100));
w=w-f-(w-f-((w-f)%100))+300;
if(w-g>=0)
{ q=q+(w-g-((w-g)%100));
w=w-g-(w-g-((w-g)%100))+300;
if(w-h>=0)
q=q+(w-h-((w-h)%100));
w=w-h-(w-h-((w-h)%100))+300;
if (w-i>=0)
{ q=q+(w-i-((w-i)%100));
w=w-i-(w-i-((w-i)%100))+300;
if (w-j>=0)
{ q=q+(w-j-((w-j)%100));
w=w-j-(w-j-((w-j)%100))+300;
if(w-k>=0)
{
q=q+(w-k-((w-k)%100));
w=w-k-(w-k-((w-k)%100))+300;
if(w-l>=0)
{ q=q+(w-l-((w-l)%100));
w=w-l-(w-l-((w-l)%100))+300;
if (w-m>=0)
{q=q*1.2;
n=w-m+q;
out<<n-300;

}else cout<<-12;
}else cout<<-11;

}else cout<<-10;
}else cout<<-9;
}else cout<<-8;
}else cout<<-7;

}else cout<<-6;

}
else cout<<-5;
}
else cout<<-4;
}
else cout<<-3;
}
else
cout<<-2;
}
else
cout<<-1;

return 0;
}

此题略水。纯枚举，用好整除和求模运算，不会太难的。另外，注意别模0，否则，你懂得。。。

代码如下：
```
01.var i,s,p,z:integer;

02. a:array[1..12]of integer;

03. tt:real;

04. f:boolean;

05.begin

06. s:=0;p:=0;z:=0;f:=true;

07. for i:=1 to 12 do begin

08. readln(a[i]);

09. s:=s+300-a[i];

10. if(s<0)and f then begin
11. z:=i;
12. f:=false;
13. end;
14. if s>=100 then begin

15. p:=p+(s div 100)*100;

16. s:=s mod 100;

17. end;

18. end;

19. tt:=s+p*1.2;

20. if z=0 then writeln(tt:0:0)

21. else writeln('-',z);

22.end.

#include<iostream>
using namespace std;

int month[12];

int main() {
    int mother = 0;
    int jingjing = 0;
    
    for(int i = 0 ; i < 12 ; ++i) {
        cin >> month[i];    
    }
    
    for(int i = 0 ; i < 12 ; ++i) {
         jingjing = jingjing + 300 - month[i];  
         if(jingjing < 0) {
            cout << "-"<<i + 1<<endl;
            return 0;
         }          
         
         while(jingjing >= 100) {
            jingjing -= 100;
            mother += 100;
         }
    }
    
    cout << 1.2 * mother + jingjing << endl; 
    return 0;   
    
} 

#include <iostream>
using namespace std;

int main() {
int money = 0;
int store = 0;
int i = 0;
int moneyNeedNow = 0;
int moneyWillStore = 0;
int flag = 0;//不够
while (i++ < 12) {
cin >> moneyNeedNow;
money = money+ 300- moneyNeedNow;
if (money >= 100) {
moneyWillStore = 100 * (money / 100);
money -= moneyWillStore;
store += moneyWillStore;
}
else if (money < 0) {
flag = 1;
break;
}
}
if (flag == 1) {
cout << "-" << i << endl;
}
else {
cout << money + store * 1.2 << endl;
}
return 0;
}

#include <stdio.h>

int main()
{
    int str[12];
    int i, money = 0, m = 0;
    for (i = 0;i < 12;i++) scanf("%d", &str[i]);
    for (i = 1;(money >= 0)&&(i<13);i++)
    {
        money += 300 - str[i - 1]; //当前月份剩的钱
        while ((money>=0)&&(money / 100))
        {
            money -= 100;
            m++;
        }
    }
    if (money >= 0) printf("%d\n", 120 * m + money);
    else printf("-%d\n", i-1);
}

#include <stdio.h>

int main()
{
int money[12],i=0;
int in=0,out=0,total,con=1,month,TotalOut=0;
for (i=0; i<12;i++)
{
scanf("%d",&money[i]);
}
i=0;
for (i=0;i<12;i++)
{
in+=300;
in-=money[i];
if (in<0)
{
month=i+1;
con=0;
break;
}
out=in-in%100;
TotalOut+=out;
in-=out;
}
if (con==1)
{
total=in+TotalOut*1.2;
printf("%d",total);
}
else
{
printf("-%d",month);
}
return 0;
}

#Python 解法，请多指教
def process(budget, balance, Mama):

    if balance + 300 - budget >= 100:
        Mama = 100 * ((balance + 300 - budget) // 100) + Mama
        balance = (balance + 300 - budget) % 100
    
         
    else:
        balance = balance + 300 - budget
    return balance, Mama


balance = 0
Mama = 0

for i in range(1, 13):
    budget = int(input())
    balance, Mama = process(budget, balance, Mama)
    
    if balance < 0:
        print("-{}".format(i))
        break
    if i == 12:
        print(int(Mama*1.2 + balance))
    i = i + 1
    

c++代码
#include<bits/stdc++.h>
using namespace std;
int main(){
int a,s=0,t=0;
for(int i=1;i<=12;i++){
cin>>a;
s=s+300-a;
if(s<0){
cout<<"-"<<i;
return 0;
}
if(s>=100){
t=t+s/100*100;
s=s-s/100*100;
}
}
cout<<fixed<<setprecision(0)<<s+t*1.2;
return 0;
}

program jingjing;
var n,ans,m,i:longint;
a:array[1..12] of longint;
begin
n:=0;
ans:=0;
m:=0;
for i:=1 to 12 do
readln(a[i]);
for i:=1 to 12 do
begin
n:=n+300-a[i];
if n<0 then
begin
m:=-i;
writeln(m);
exit;
end;
if n>100 then
begin
ans:=ans+n div 100;
n:=n mod 100;
end;
end;
n:=n+ans*120;
writeln(n);
end.

program jingjing;
var a:array [1..12] of longint;
yuan,cun,c1,c2,i,n:longint;
begin
yuan:=0;
for i:=1 to 12 do
readln(a[i]);
for i:=1 to 12 do
begin
yuan:=yuan+300-a[i];
if yuan<0 then
begin n:=-i; writeln(n); exit; end;
if yuan>=100 then
begin
cun:=cun+yuan div 100;
yuan:=yuan mod 100;
end;
end;
cun:=cun*120;
yuan:=yuan+cun;
writeln(yuan);
end.