编译失败

#include<bits/stdc++.h> 
#include<iostream>
#include<cstring>
#include<cmath>
using namespace std;
const int N = 10010;
int n;
int col;
bool iszero;
vector<int> a;
int main()
{
    int x;
    cin >> n;
    while(cin >> x)a.push_back(x);
    for(int i = 0;i<a.size();i++)
    {
        iszero = iszero ? false :true;
        int k = a[i];
        for(int j=0;j<k;j++)
        {
            cout<<(iszero?"0":"1");
            if(col==n-1)puts("");
            col = (col+1)%n;
        }
    }
    return 0;
}