#include <bits/stdc++.h> #define ios ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0) #define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout) #define all(a) a.begin() , a.end() #define F first #define S second using namespace std; using ll = long long; const int N = 2e5+5 , inf = 2e9 + 7; const ll INF = 1e18 , mod = 1e9+7 , P = 6547; int dp[N], pos[N], a[N]; int get(int l, int r) { int cnt = 0; for(int i = r; i >= l; i --) { for(int j = i+1; j <= r; j ++) { if(pos[i] < pos[j]) cnt ++; } for(int j = l-1; j >= 1; j --) { if(pos[i] < pos[j]) cnt ++; } } return cnt; } void solve(int tc) { int n; cin >> n; for(int i = 1; i <= n; i ++) { cin >> a[i]; pos[a[i]] = i; } for(int i = 1; i <= n; i ++) { dp[i] = inf; for(int j = i; j >= 1; j --) { dp[i] = min(dp[i], get(j, i) + dp[j-1]); } } cout << dp[n]; } /* */ main() { ios; int tt = 1 , tc = 0; // cin >> tt; while(tt --) { solve(++tc); } return 0; }

Main.cpp:47:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   47 | main() {
      | ^~~~