Submission #961412

#	Time	Username	Problem	Language	Result	Execution time	Memory
961412		noobcodur	Group Photo (JOI21_ho_t3)	C++14	Compilation error	0 ms	0 KiB

Main

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

using ld = long double;

#define int long long
#define pii pair<int,int>
#define forn(i,j) for(int i = 0; i < j; ++i)
#define forrange(i,j,k) for(int i = j; i < k; ++i)
#define vi vector<int>
#define vpii vector<pii>
#define f first
#define s second
#define pb push_back
#define all(x) x.begin(),x.end()

const int MOD = 1e9+7; const int INF = 1e17+1; const int maxN = 5e3+1;

void setIO(string name){
	ios_base::sync_with_stdio(0);
	cin.tie(0);

	if(!name.empty()){
		freopen((name + ".in").c_str(),"r",stdin);
		freopen((name + ".out").c_str(),"w",stdout);
	}
}

int dp[maxN],a[maxN],pos[maxN],small[maxN];

int bit1[maxN],bit2[maxN];

void update1(int idx){
	while(idx < maxN){
		bit1[idx]++; idx += idx&-idx;
	}
}

int query1(int idx){
	int res = 0;
	while(idx){
		res += bit1[idx]; idx -= idx&-idx;
	}

	return res;
}

void update2(int idx){
	while(idx < maxN){
		bit2[idx]++; idx += idx&-idx;
	}
}

int query2(int idx){
	int res = 0;
	while(idx){
		res += bit2[idx]; idx -= idx&-idx;
	}

	return res;
}

void init(int n){
	forrange(i,1,n+1){
		bit2[i] = 0;
	}
}

signed main(){
	setIO("");
	int n; cin >> n;

	forrange(i,1,n+1){
		cin >> a[i]; pos[a[i]] = i;
	}

	dp[0] = 0;

	forrange(i,1,n+1){
		dp[i] = INF;
		update1(pos[i]);
		small[i] = query1(n)-query1(pos[i]);
		int cost = 0;
		for(int j = i; j; --j){
			cost += small[j]; //number of elements k < j having pos[k] > pos[j]

			cost += query2(n)-query2(pos[j]); //number of elements k > j, having pos[k] > pos[j]
			cost -= query(pos[j]-1); //number of elements k > j, having pos[k] < pos[j]

			dp[i] = min(dp[i],dp[j-1]+cost);
			update2(pos[j]);
		}

		init(n);
	}

	cout << dp[n] << endl;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:88:12: error: 'query' was not declared in this scope; did you mean 'query2'?
   88 |    cost -= query(pos[j]-1); //number of elements k > j, having pos[k] < pos[j]
      |            ^~~~~
      |            query2
Main.cpp: In function 'void setIO(std::string)':
Main.cpp:24:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |   freopen((name + ".in").c_str(),"r",stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:25:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |   freopen((name + ".out").c_str(),"w",stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~