Submission #1079631

#	Time	Username	Problem	Language	Result	Execution time	Memory
1079631		ALeonidou	Paint By Numbers (IOI16_paint)	C++17	100 / 100	526 ms	179288 KiB

paint

#include "paint.h"
#include <bits/stdc++.h>
 
using namespace std;
 
#define ll int
#define F first
#define S second
#define sz(x) (ll)x.size()
#define pb push_back
 
typedef vector <ll> vi;
typedef pair <ll,ll> ii;
typedef vector <ii> vii;
 
#define dbg(x) cout<<#x<<": "<<x<<endl;
#define dbg2(x,y) cout<<#x<<": "<<x<<" "<<#y<<": "<<y<<endl;
#define dbg3(x,y,z) cout<<#x<<": "<<x<<" "<<#y<<": "<<y<<" "<<#z<<": "<<z<<endl;
 
void printVct(vi &v){
    for (ll i= 0; i<sz(v); i++){
        cout<<v[i]<<" ";
    }
    cout<<endl;
}
 
#define N 200001
#define K 101

ll dp[N+1][K+1][2];

vi v,p;
vi w,b;
string s;

ll getSum(ll l, ll r){
    if (l == 0) return p[r];
    return p[r] - p[l-1];
}

bool solve(ll n, ll k, bool prevBlack){     //O(n * k)
    if (n >= sz(s)){
        return (k == sz(v));
    } 
    
    if (dp[n][k][prevBlack] != -1) return dp[n][k][prevBlack];

    if (s[n] == '_'){
        bool ans = solve(n+1, k, false);
        w[n] |= ans;
        return dp[n][k][prevBlack] = ans;
    }

    bool canBeBlack = true;
    if (prevBlack || k >= sz(v) || n + v[k] > sz(s)) canBeBlack = false;
    if (canBeBlack) canBeBlack = (getSum(n, n+v[k]-1) == 0);

    if (s[n] == 'X'){
        bool ans = (canBeBlack && solve(n+v[k], k+1, true));
        b[n] = max(b[n], ans * v[k]);
        return dp[n][k][prevBlack] = ans;
    }

    bool ans1 = solve(n+1, k, false);
    bool ans2 = (canBeBlack && solve(n+v[k], k+1, true));
    w[n] |= ans1;
    b[n] = max(b[n], ans2 * v[k]);
    return dp[n][k][prevBlack] = (ans1 || ans2);
}
 
string solve_puzzle(string st, vi arr) {
    v = arr;
    s = st;
    ll n = sz(s);
    ll k = sz(v);
 
    for (ll k =0; k<=N; k++){
        for (ll j =0; j<=K; j++){
            dp[k][j][0] = -1;
            dp[k][j][1] = -1;
        }
    }
    w.resize(n);
    b.resize(n);

    p.resize(sz(s));
    p[0] = (s[0] == '_');
    for (ll j =1; j<sz(s); j++){
        p[j] = p[j-1] + (s[j] == '_');
    }

    solve(0,0,false);

    ll b_boost = 0;
    for (ll i =0; i<n; i++){
        if (b[i] || b_boost){
            b_boost = max(b[i], b_boost);
            b[i] = 1;
        }
        b_boost = max(b_boost-1, 0);
    }

    for (ll i =0; i<n; i++){
        if (s[i] == '.'){
            if (w[i] && b[i]) s[i] = '?';
            else if (w[i]) s[i] = '_';
            else s[i] = 'X';
        }
    }

    return s;
}
 
/*
..........
2 3 4
 
..._._....
1 3
 
.._._.....................
2 1 19
 
_........_
3 2 2 2
 
....._.
2 2 2
 
..........
3 1 3 2
*/

Compilation message (stderr)

paint.cpp: In function 'bool solve(int, int, bool)':
paint.cpp:51:36: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   51 |         return dp[n][k][prevBlack] = ans;
      |                ~~~~~~~~~~~~~~~~~~~~^~~~~
paint.cpp:61:36: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   61 |         return dp[n][k][prevBlack] = ans;
      |                ~~~~~~~~~~~~~~~~~~~~^~~~~
paint.cpp:68:32: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   68 |     return dp[n][k][prevBlack] = (ans1 || ans2);
      |            ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
paint.cpp: In function 'std::string solve_puzzle(std::string, vi)':
paint.cpp:75:8: warning: unused variable 'k' [-Wunused-variable]
   75 |     ll k = sz(v);
      |        ^

• 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