Submission #1359572

#TimeUsernameProblemLanguageResultExecution timeMemory
1359572AMel0nPaint By Numbers (IOI16_paint)C++20
32 / 100
1 ms344 KiB
#include "paint.h"
#include <bits/stdc++.h>
using namespace std;
string solve_puzzle(string S, vector<int> C) {
    int N = S.size(), K = C.size();
    string res = S;
    vector<int> pX(N+4), p_(N+4);
    for(int i = 2; i <= N+1; i++) {
        pX[i] += pX[i-1] + (S[i-2] == 'X');
        p_[i] += p_[i-1] + (S[i-2] == '_');
    }
    for(int i = N+2; i <= N+3; i++) {
        pX[i] += pX[i-1];
        p_[i] += p_[i-1];
    }
    auto qX = [&](int l, int r, int add) {
        l += add, r += add;
        if (!l) return pX[r];
        return pX[r] - pX[l-1];
    };
    auto q_ = [&](int l, int r, int add) {
        l += add, r += add;
        if (!l) return p_[r];
        return p_[r] - p_[l-1];
    };
    vector<vector<int>> dp1(K+1, vector<int>(N+2)), dp2(K+1, vector<int>(N+2)); // can the kth block of black cells end/start at i
    vector<vector<int>> canX(K+1, vector<int>(N)); // can i be a black cell in the kth block of black cells 
    for(int i = 0; i <= N; i++) {
        dp1[0][i] = qX(0, i+1, 0) == 0;
        if (i != N) canX[0][i] |= dp1[0][i];
    }
    for(int k = 1; k <= K; k++) {
        for(int i = 2; i <= N+1; i++) {
            if (i-C[k-1]+1 >= 2 && !qX(i-C[k-1], i-C[k-1], 0) && !q_(i-C[k-1]+1, i, 0)) dp1[k][i] |= dp1[k-1][i-C[k-1]-1];
        }
        queue<int> isX;
        for(int i = N+1; i >= 2; i--) {
            while(isX.size() && isX.front() >= i+C[k-1]) isX.pop();
            int yes = dp1[k][i];
            if (isX.size()) yes |= 1;
            canX[k-1][i-2] |= yes;
            if (dp1[k][i]) isX.push(i);
        }
    }

    for(int i = 1; i <= N+1; i++) {
        dp2[K][i] = qX(i-1, N+1, 2) == 0;
        if (i != 1) canX[K][i-2] &= dp2[K][i];
    }
    for(int k = K-1; k >= 0; k--) {
        for(int i = N-1; i >= 0; i--) {
            if (i+C[k]-1 < N && !qX(i+C[k], i+C[k], 2) && !q_(i, i+C[k]-1, 2)) dp2[k][i] |= dp2[k+1][i+C[k]+1];
        }
        queue<int> isX;
        for(int i = 0; i <= N-1; i++) {
            while(isX.size() && isX.front() <= i-C[k]) isX.pop();
            int yes = dp2[k][i];
            if (isX.size()) yes |= 1;
            canX[k][i] &= yes;
            if (dp2[k][i]) isX.push(i);
        }
    }

    for(int k = 1; k <= K; k++) {
        for(int i = 2; i <= N+1; i++) {
            if (S[i-2] != 'X') dp1[k][i] |= dp1[k][i-1];
        }
    }
    for(int k = K-1; k >= 0; k--) {
        for(int i = N-1; i >= 0; i--) {
            if (S[i] != 'X') dp2[k][i] |= dp2[k][i+1];
        }
    }
    
    for(int i = 0; i < N; i++) {
        if (S[i] != '.') continue;
        for(int k = 0; k <= K; k++) {
            if (dp2[k][i+1] && dp1[k][i-1+2]) {
                res[i] = '_';
            }
        }
    }
    for(int i = 0; i < N; i++) {
        if (S[i] != '.') continue;
        for(int k = 0; k <= K; k++) {
            if (canX[k][i]) {
                if (res[i] == '.') res[i] = 'X';
                else res[i] = '?';
            }
        }
    }
    return res;
}
#Result Execution timeMemoryGrader output
Fetching results...
#Result Execution timeMemoryGrader output
Fetching results...
#Result Execution timeMemoryGrader output
Fetching results...
#Result Execution timeMemoryGrader output
Fetching results...
#Result Execution timeMemoryGrader output
Fetching results...
#Result Execution timeMemoryGrader output
Fetching results...
#Result Execution timeMemoryGrader output
Fetching results...