Submission #1598113

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Source Code Expand

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

const int N = 100010;

int n, a[N];
int ans;

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0);
	cin >> n;
	for (int i = 1; i <= n; ++i) {
		cin >> a[i];
		a[i] = (a[i] == i);
	}

	int cnt = 0;
	for (int i = 1; i <= n; ++i) {
		if (a[i] == 1) {
			++cnt;
		} else {
			ans += (cnt + 1) / 2;
			cnt = 0;
		}
	}
	ans += (cnt + 1) / 2;
	cout << ans << endl;
}

Submission Info

Judge Result