求调40分代码

#include<bits/stdc++.h>
using namespace std;

const int N = 1e5;

int n,a[N],msum[N],wsum[N],maxn;

int main() {
	cin >> n;
	for(int i = 1;i<=n;i++) {
		cin >> a[i];
		msum[i] = msum[i - 1];
		wsum[i] = wsum[i - 1];
		if(a[i] == 1) {
			msum[i]++;
		}else {
			wsum[i]++;
		}
	}
	for(int i = 1;i<=n;i++) {
		for(int j = i;j>=1;j--) {
			if(msum[i] - msum[j] == wsum[i] - wsum[j]) {
				maxn = max(i - j,maxn);
			}
		}
	}
	cout << maxn;
	return 0;
}