只对了一半测试点，大佬们看看哪些不对啊。。。

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
int main()
{
    int a, b, c;
    int sum = 0;
    int min;
    cin >> a >> b >> c;
    if(a>b)
    {
        int t;
        t = a;
        a = b;
        b = t;
    }
    if(a != b)
    {
        if((a+c)>b)
        {
            c = c - (b - a);
            b += (c / 2);
            a = b;
            min = a;
        }
        else
        {
            a += c;
            min = a;
        }
    }
    else
    {
        a += (c / 2);
        min = a;
    }
    int i = 1;
    while(1)
    {
        min -= i;
        if (min < 0)
        {
            break;
        }
        i++;
        sum++;
    }
    cout << sum;
    return 0;
}