https://cses.fi/paste/17d0c105267da8d76a177b/
#include<bits/stdc++.h>using namespace std;char nl = '\n';void solve() {int n; cin >> n;int ans = 0;vector<int> a(n + 1);for(int i = 0; i < n; i++) {int x; cin >> x;a[x] = i;}for(int i = 2; i <= n; i++) {if(a[i] < a[i - 1]) ans++;}cout << ans + 1 << nl;}int main() {int t = 1;// cin >> t;while(t--) {solve();}return 0;}