Submission #811268

#	Time	Username	Problem	Language	Result	Execution time	Memory
811268		becaido	Paint By Numbers (IOI16_paint)	C++17	100 / 100	231 ms	13680 KiB

paint

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,popcnt,sse4,abm")
#include <bits/stdc++.h>
using namespace std;

#ifndef WAIMAI
#include "paint.h"
#endif

#ifdef WAIMAI
#define debug(HEHE...) cout << "[" << #HEHE << "] : ", dout(HEHE)
void dout() {cout << '\n';}
template<typename T, typename...U>
void dout(T t, U...u) {cout << t << (sizeof...(u) ? ", " : ""), dout(u...);}
#else
#define debug(...) 7122
#endif

#define ll long long
#define Waimai ios::sync_with_stdio(false), cin.tie(0)
#define FOR(x,a,b) for (int x = a, I = b; x <= I; x++)
#define pb emplace_back
#define F first
#define S second

/*
r[i] = l[i] + c[i]
r[i] < l[i + 1]
0 <= l[0]
r[k - 1] <= n
*/

const int SIZE = 2e5 + 5;
const int MAX = 105;

int n, k;
string ans;
int pre[SIZE], x[SIZE], y[SIZE];
bitset<SIZE> L[2][MAX], R[2][MAX];

string solve_puzzle(string s, vector<int> c) {
    n = s.size();
    k = c.size();
    c.insert(c.begin(), 0);
    ans.resize(n, '?');
    FOR (i, 0, n - 1) pre[i] = (i ? pre[i - 1] : 0) + (s[i] == '_');
    auto sum = [&](int l, int r) {
        return pre[r] - (l ? pre[l - 1] : 0);
    };
    FOR (i, 0, k) FOR (j, 0, n - 1) {
        if (s[j] != 'X') L[0][i][j] = (i == 0 || j > 0) && (j == 0 || L[0][i][j - 1] || L[1][i][j - 1]);
        if (i > 0 && j >= c[i] - 1 && sum(j - c[i] + 1, j) == 0) L[1][i][j] = (i == 1 && j == c[i] - 1) || (j >= c[i] && L[0][i - 1][j - c[i]]);
    }
    for (int i = k + 1; i >= 1; i--) for (int j = n - 1; j >= 0; j--) {
        if (s[j] != 'X') R[0][i][j] = (i == k + 1 || j < n - 1) && (j == n - 1 || R[0][i][j + 1] || R[1][i][j + 1]);
        if (i <= k && j + c[i] <= n && sum(j, j + c[i] - 1) == 0) R[1][i][j] = (i == k && j + c[i] == n) || (j + c[i] < n && R[0][i + 1][j + c[i]]);
    }
    FOR (i, 0, k) FOR (j, 0, n - 1) {
        if (i >= 1 && L[1][i][j] && ((i == k && j == n - 1) || (j < n - 1 && R[0][i + 1][j + 1]))) {
            x[j - c[i] + 1]++;
            x[j + 1]--;
        }
        if (L[0][i][j] && R[0][i + 1][j]) y[j] = 1;
    }
    FOR (i, 0, n - 1) {
        if (!x[i]) ans[i] = '_';
        if (!y[i]) ans[i] = 'X';
        x[i + 1] += x[i];
    }
    return ans;
}

/*
in1
..........
2 3 4
out1
??X???XX??

in2
........
2 3 4
out2
XXX_XXXX

in3
..._._....
1 3
out3
???___????

in4
.X........
1 3
out4
?XX?______
*/

#ifdef WAIMAI
const int S_MAX_LEN = 200 * 1000;
char buf[S_MAX_LEN + 1];

int main() {
    assert(1 == scanf("%s", buf));
    string s = buf;
    int c_len;
    assert(1 == scanf("%d", &c_len));
    vector<int> c(c_len);
    for (int i = 0; i < c_len; i++) {
        assert(1 == scanf("%d", &c[i]));
    }
    string ans = solve_puzzle(s, c);


    printf("%s\n", ans.data());
    return 0;
}
#endif

• 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