Submission #126810

#	Time	Username	Problem	Language	Result	Execution time	Memory
126810		Sorting	Paint By Numbers (IOI16_paint)	C++14	100 / 100	531 ms	54664 KiB

paint

#include <bits/stdc++.h>

using namespace std;

const int N = 2e5 + 7;
const int K = 1e2 + 7;

pair<bool, bool> dp[N][K];
string s, ans;
vector<int> c;
int v[N];
int a[N], n;

void make_zero(int idx){
	if(ans[idx] == '.'){
		ans[idx] = '_';
	}
	else{
		if(ans[idx] != '_'){
			ans[idx] = '?';
		}
	}
}

void make_x(int idx){
	if(ans[idx] == '.'){
		ans[idx] = 'X';
	}
	else{
		if(ans[idx] != 'X'){
			ans[idx] = '?';
		}
	}
}

bool solve(int i1, int i2){
	//cout << i1 << " " << i2 << endl;

	if(i1 == n){
		if(i2 == c.size()){
			return 1;
		}
		return 0;
	}

	if(dp[i1][i2].second){
		return dp[i1][i2].first;
	}

	dp[i1][i2].second = true;
	dp[i1][i2].first = false;
	//cout << i1 << " " << i2 << endl;

	if(s[i1] == '.' || s[i1] == '_'){
		bool b = solve(i1 + 1, i2);
		
		if(b){
			make_zero(i1);
			dp[i1][i2].first = true;
		}
	}
	if(a[i1] >= c[i2] && (i1 + c[i2] == n || s[i1 + c[i2]] != 'X')){
		bool b;
		if(i1 + c[i2] == n){
			b = solve(i1 + c[i2], i2 + 1);
			if(b){
				dp[i1][i2].first = true;
				v[i1]++;
				v[i1 + c[i2]]--;
			}
		}
		else{
			b = solve(i1 + c[i2] + 1, i2 + 1);
			if(b){
				make_zero(i1 + c[i2]);
				dp[i1][i2].first = true;
				v[i1]++;
				v[i1 + c[i2]]--;
			}
		}
	}

	return dp[i1][i2].first;
}

string solve_puzzle(string _s, vector<int> _c){
	n = _s.size();

	s = _s;
	for(int i = 0; i < (int)_c.size(); i++){
		c.push_back(_c[i]);
	}

	if(s[n - 1] == 'X' || s[n - 1] == '.'){
		a[n - 1] = 1;
	}
	else{
		a[n - 1] = 0;
	}
	for(int i = n - 2; i >= 0; i--){
		if(s[i] == 'X' || s[i] == '.'){
			a[i] = a[i + 1] + 1;
		}
		else{
			a[i] = 0;
		}
	}

	//for(int i = 0; i < n; i++){
	//	cout << a[i] << " ";
	//}
	//cout << endl;

	ans = s;

	solve(0, 0);

	int curr = 0;

	for(int i = 0; i < n; i++){
		curr += v[i];

		if(curr > 0){
			make_x(i);
		}
	}

	return ans;
}

/*int main(){
	string _s;
	vector<int> _c;
	int k;

	cin >> _s;

	cin >> k;

	for(int i = 0; i < k; i++){
		int x;

		cin >> x;

		_c.push_back(x);
	}

	cout << solve_puzzle(_s, _c) << endl;

	return 0;
}*/
/*
..........
2
3 4
*/

Compilation message (stderr)

paint.cpp: In function 'bool solve(int, int)':
paint.cpp:40:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i2 == c.size()){
      ~~~^~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 3 / 3
• Subtask 3: 22 / 22
• Subtask 4: 27 / 27
• Subtask 5: 21 / 21
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10