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Submission #869452

# Submission time Handle Problem Language Result Execution time Memory
869452 2023-11-04T11:33:21 Z Hakiers Monochrome Points (JOI20_monochrome) C++17
0 / 100
 1 ms 348 KB 
#include <bits/stdc++.h>
using namespace std;
const int BASE = 1 << 18;
int TREE[BASE << 1];
int n;
string monochrome;
queue<int> BPOS;
queue<int> WPOS;

void add(int v, int val){
	v+=BASE;
	TREE[v] += val;
	v/=2;
	while(v > 0){
		int l = 2*v, r = 2*v+1;
		TREE[v] = TREE[l] + TREE[r];
		v/=2;
	}
}
int query(int a, int b){
	a += BASE - 1;
	b += BASE + 1;
	
	int res = 0;
	while(a/2 != b/2){
		if(!(a&1)) res += TREE[a+1];
		if(b&1) res += TREE[b-1];
		a/=2; b/=2;
	}
	return res;
}

int solve(){
	int res = 0;
	
	for(int i = 2*n; i >= n+1; i--){
		if(monochrome[i] == 'B'){
			int v = WPOS.front();
			WPOS.pop();
			//cout << "query: " << query(v, BASE-1) << "\n";
			res += query(v, BASE-1);
			add(v, 1);
		}
		else if(monochrome[i] == 'W'){
			int v = BPOS.front();
			BPOS.pop();
			//cout << "query: " << query(v, BASE-1) << "\n";
			res += query(v, BASE-1);
			add(v, 1);
		}
	}

	return res;
}

int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cin >> n;
	cin >> monochrome;
	monochrome = "#" + monochrome;
	for(int i = n; i >= 1; i--){
		if(monochrome[i] == 'B')
			BPOS.push(i);
		else if(monochrome[i] == 'W')
			WPOS.push(i);
	}
	
	cout << solve() << "\n";

}

Subtask #1
0.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 344 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Incorrect 1 ms 348 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #2
0.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 344 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Incorrect 1 ms 348 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #3
0.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 344 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Incorrect 1 ms 348 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #4
0.0 / 65.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 344 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Incorrect 1 ms 348 KB Output isn't correct
6 Halted 0 ms 0 KB -