Submission #853355

#	Time	Username	Problem	Language	Result	Execution time	Memory
853355		hngwlog	Paint By Numbers (IOI16_paint)	C++14	90 / 100	367 ms	524288 KiB

paint

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

#define fi first
#define se second
#define _size(x) (int)x.size()
#define BIT(i, x) ((x >> i) & 1)
#define MASK(n) ((1 << n) - 1)
#define REP(i, n) for (int i = 0, _n = (n); i < _n; i++)
#define FOR(i, a, b) for (int i = a, _b = (b); i <= _b; i++)
#define FORD(i, a, b) for (int i = a, _b = (b); i >= _b; i--)
#define FORB1(i, mask) for (int i = mask; i > 0; i ^= i & - i)
#define FORB0(i, n, mask) for (int i = ((1 << n) - 1) ^ mask; i > 0; i ^= i & - i)
#define FORALL(i, a) for (auto i: a)
#define fastio ios_base::sync_with_stdio(0); cin.tie(0);

string solve_puzzle(string s, vector<int> c) {

    int n = _size(s), k = _size(c);
    s = ' ' + s;
    vector<vector<int>> cnt(n + 1, vector<int>(2));
    FOR(i, 1, n) {
        REP(type, 2) cnt[i][type] = cnt[i - 1][type];
        if (s[i] == 'X') cnt[i][0]++;
        else if (s[i] == '_') cnt[i][1]++;
    }
    vector<vector<vector<short int>>> f(n + 1, vector<vector<short int>>(k + 1, vector<short int>(2)));
    f[0][0][1] = 1;
    FOR(i, 1, n) {
        FOR(j, 0, k) {
            REP(type, 2) {
                if ((s[i] == 'X' && type) || (s[i] == '_' && !type)) continue;
                if (s[i] == 'X') {
                    if (!j) continue;
                    if (i < c[j - 1] || cnt[i][1] - cnt[i - c[j - 1]][1]) continue;
                    f[i][j][type] = max({f[i][j][type], f[i - c[j - 1]][j - 1][1]});
                }
                else if (s[i] == '_') f[i][j][type] = max({f[i][j][type], f[i - 1][j][0], f[i - 1][j][1]});
                else {
                    f[i][j][1] = max({f[i][j][1], f[i - 1][j][0], f[i - 1][j][1]});
                    if (!j) continue;
                    if (i < c[j - 1] || cnt[i][1] - cnt[i - c[j - 1]][1]) continue;
                    f[i][j][0] = max({f[i][j][0], f[i - c[j - 1]][j - 1][1]});
                }
            }
        }
    }
    FORD(i, n, 1) {
        FORD(j, k, 0) {
            REP(type, 2) {
                if (!f[i][j][type]) continue;
                if (j == k && cnt[n][0] - cnt[i][0] == 0) f[i][j][type]++;
                if (f[i][j][type] == 1) continue;
                if (type == 1) {
                    if (f[i - 1][j][0] == 1) f[i - 1][j][0]++;
                    if (f[i - 1][j][1] == 1) f[i - 1][j][1]++;
                }
                else if (f[i - c[j - 1]][j - 1][1] == 1) f[i - c[j - 1]][j - 1][1]++;
            }
        }
    }
    vector<int> _cnt(n + 2);
    FOR(i, 1, n) {
        FOR(j, 1, k) if (f[i][j][0] > 1) _cnt[i - c[j - 1] + 1]++, _cnt[i + 1]--;
    }
    FOR(i, 1, n) _cnt[i] += _cnt[i - 1];
    string ans = "";
    FOR(i, 1, n) {
        if (s[i] == 'X') ans += 'X';
        else if (s[i] == '_') ans += '_';
        else {
            int res = 0;
            FOR(j, 0, k) if (f[i][j][1] > 1) res++;
            if (_cnt[i]) {
                if (res) ans += '?';
                else ans += 'X';
            }
            else ans += '_';
        }
    }
    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: 0 / 10