Codeforces Round #310 (Div. 2)--A(简单题)

#include <cstdio>
#include <cmath>
#include <cstring>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <set>
#include <vector>
#include <sstream>
#include <queue>
#include <typeinfo>
#include <fstream>
#include <map>
#include <stack>
using namespace std;
typedef long long ll;
const int maxn=200010;
char num[maxn];
int main()
{
    int n,zero=0,one=0;
    scanf("%d",&n);
    scanf("%s",num);
    for(int i=0;i<n;i++){
        if(num[i]==‘0‘) zero++;
        if(num[i]==‘1‘) one++;
    }
    if(zero==one) printf("0\n");
    else printf("%d\n",zero>one?zero-one:one-zero);
    return 0;
}