Submission #287497

#	Time	Username	Problem	Language	Result	Execution time	Memory
287497		Shafin666	Paint By Numbers (IOI16_paint)	C++14	90 / 100	2009 ms	318472 KiB

paint

#include <bits/stdc++.h>
#define pb push_back
#define pii pair<ll, ll>
#define nyan "(=^･ω･^=)"
#define read_input         freopen("in.txt","r", stdin)
#define print_output       freopen("out.txt","w", stdout)
typedef long long ll;
typedef long double ld;
using namespace std;

const int maxn = 2e5+10, maxk = 103;
int n, k;

int dp1[maxn][maxk], dp2[maxn][maxk];
int dash[maxn], crs[maxn]; 
int lft[maxn], rgt[maxn], aux[maxn];

int p1[maxn][maxk], p2[maxn][maxk];
string str;

int x[maxn], y[maxn];

bool okx(int l, int r) {
    if(l >= 2 && str[l-2] == 'X') return 0;
    if(r < n && str[r] == 'X') return 0;
    return (dash[r] - dash[l-1] == 0);
}

std::string solve_puzzle(std::string s, std::vector<int> c) {
    n = s.length(); str = s;
    k = c.size();

    for(int i = 1; i <= n; i++) {
        dash[i] = dash[i-1] + (str[i-1] == '_');
        crs[i] = crs[i-1] + (str[i-1] == 'X');
    }

    dp1[0][0] = 1; p1[0][0] = 1;
    for(int i = 1; i <= n && str[i-1] != 'X'; i++) p1[i][0] = 1;
    for(int j = 1; j <= k; j++) {
        for(int i = 1; i <= n; i++) {

            int f1 = p1[i-1][j], f2;
            if(i < c[j-1]) f2 = 0;
            else if(j > 1) f2 = p1[i - c[j-1] - 1][j-1] & okx(i - c[j-1] + 1, i);
            else f2 = p1[i - c[j-1]][j-1] & okx(i - c[j-1] + 1, i);

            if(str[i-1] == '_') p1[i][j] = f1;
            else if(str[i-1] == 'X') p1[i][j] = f2;
            else p1[i][j] = f1 | f2;

            dp1[i][j] = f2;
            dp1[i][0] = p1[i][0];
        }
    }

    reverse(str.begin(), str.end());
    reverse(c.begin(), c.end());

    for(int i = 1; i <= n; i++) {
        dash[i] = dash[i-1] + (str[i-1] == '_');
        crs[i] = crs[i-1] + (str[i-1] == 'X');
    }

    dp2[0][0] = 1; p2[0][0] = 1;
    for(int i = 1; i <= n && str[i-1] != 'X'; i++) p2[i][0] = 1;
    for(int j = 1; j <= k; j++) {
        for(int i = 1; i <= n; i++) {

            int f1 = p2[i-1][j], f2;
            if(i < c[j-1]) f2 = 0;
            else if(j > 1) f2 = p2[i - c[j-1] - 1][j-1] & okx(i - c[j-1] + 1, i);
            else f2 = p2[i - c[j-1]][j-1] & okx(i - c[j-1] + 1, i);

            if(str[i-1] == '_') p2[i][j] = f1;
            else if(str[i-1] == 'X') p2[i][j] = f2;
            else p2[i][j] = f1 | f2;

            dp2[i][j] = f2;
            dp2[i][0] = p2[i][0];
        }
    }

    for(int j = 0; j <= k; j++) {
        for(int i = 1; 2 * i <= n; i++) {
            swap(dp2[i][j], dp2[n-i+1][j]);
            swap(p2[i][j], p2[n-i+1][j]);
        }
    } p2[n+1][0] = p2[n+2][0] = 1;
    dp2[n+1][0] = 1;

    // for(int j = 0; j <= k; j++) {
    //     for(int i = 1; i <= n; i++) 
    //         cout << dp1[i][j] << " ";
    //     cout << endl;
    // } cout << endl;

    // for(int j = 0; j <= k; j++) {
    //     for(int i = 1; i <= n; i++) 
    //         cout << dp2[i][j] << " ";
    //     cout << endl;
    // } cout << endl;


    // for(int j = 0; j <= k; j++) {
    //     for(int i = 1; i <= n; i++) 
    //         cout << p1[i][j] << " ";
    //     cout << endl;
    // } cout << endl;

    // for(int j = 0; j <= k; j++) {
    //     for(int i = 1; i <= n; i++) 
    //         cout << p2[i][j] << " ";
    //     cout << endl;
    // } cout << endl;

    reverse(c.begin(), c.end());
    for(int i = 1; i <= n; i++) {
        if(s[i-1] == '_') continue;
        for(int j = 1; j <= k; j++) {
            if(dp1[i][j] & p2[i+2][k-j]) {
                x[i+1]--; x[i - c[j-1] + 1]++;
            }
        }
    }

    for(int i = 1; i <= n; i++) {
        if(s[i-1] == 'X') continue;
        for(int j = 0; j <= k; j++) {
            y[i] = max(y[i], p1[i-1][j] & p2[i+1][k-j]);
        }
    }

    for(int i = 1; i <= n; i++) x[i] += x[i-1];
    for(int i = 1; i <= n; i++) x[i] = (x[i] > 0);

    // for(int i = 1; i <= n; i++) cout << x[i] << " "; cout << endl;
    // for(int i = 1; i <= n; i++) cout << y[i] << " "; cout << endl;

    string res = "";

    for(int i = 1; i <= n; i++) {
        if(s[i-1] == 'X') res += "X";
        else if(s[i-1] == '_') res += "_";
        else if(x[i] && y[i]) res += "?";
        else if(y[i]) res += "_";
        else res += "X";
    }

    return res;
}

• 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