Submission #957067

#	Time	Username	Problem	Language	Result	Execution time	Memory
957067		mariaclara	Paint By Numbers (IOI16_paint)	C++17	100 / 100	174 ms	85664 KiB

paint

#include "paint.h"
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef tuple<int,int,int> trio;
typedef pair<int,int> pii;
const int MAXN = 2e5+5;
const int MOD = 1e9+7;
#define all(x) x.begin(), x.end()
#define mk make_pair
#define pb push_back
#define f first
#define s second

int pref[MAXN], pref2[MAXN];
bool dpL[2][MAXN][105], dpR[2][MAXN][105], val[2][MAXN];
string solve_puzzle(string a, vector<int> c) {
    int n = a.size(), k = c.size();

    for(int i = 1; i <= n; i++) pref[i] = pref[i-1] + (a[i-1] == '_');

    dpL[0][0][0] = 1;
    for(int i = 1; i <= n; i++) {
        for(int j = 0; j <= k; j++) {
            if(a[i-1] != 'X') dpL[0][i][j] = dpL[0][i-1][j] or dpL[1][i-1][j];
            if(j and i >= c[j-1] and pref[i] == pref[i-c[j-1]])
                dpL[1][i][j] = dpL[0][i-c[j-1]][j-1];
        }
    }

    dpR[0][n+1][k] = 1;
    for(int i = n; i >= 1; i--) {
        for(int j = 0; j <= k; j++) {
            if(a[i-1] != 'X') dpR[0][i][j] = dpR[0][i+1][j];
            if(a[i-1] != '_') dpR[1][i][j] = dpR[0][i+1][j];
            if(a[i-1] != 'X' and j<k and i + c[j] <= n+1 and pref[i] == pref[i+c[j]])
                dpR[0][i][j] |= dpR[1][i+c[j]][j+1];

            if(dpL[0][i][j] and dpR[0][i][j]) val[0][i] = 1;
        }
    }

    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= k; j++) {
            if(i >= c[j-1] and pref[i] == pref[i-c[j-1]] and dpL[0][i-c[j-1]][j-1] and dpR[1][i][j])
                pref2[i-c[j-1]+1]++, pref2[i+1]--;
        }
    }

    for(int i = 1; i <= n; i++) {
        pref2[i] += pref2[i-1];
        if(pref2[i]) val[1][i] = 1;
    }

    string ans;

    for(int i = 1; i <= n; i++) {
        if(val[0][i] and val[1][i]) ans += '?';
        else if(val[0][i]) ans += '_';
        else ans += 'X';
    }

    return ans;
}

• 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