Submission #1079602

#	Time	Username	Problem	Language	Result	Execution time	Memory
1079602		ALeonidou	Paint By Numbers (IOI16_paint)	C++17	0 / 100	13 ms	8536 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;
}
 
vi v,p;
string s;

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

#define N 5001
#define K 101
ll dp[N+1][K+1][2];
bool solve(ll n, ll k, bool prevBlack){
    if (n >= sz(s)){
        return (k == sz(v));
    } 
 
    if (dp[n][k][prevBlack] != -1) return dp[n][k][prevBlack];
    
    if (s[n] == '_') return dp[n][k][prevBlack] = solve(n+1, k, false);
 
    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'){
        return dp[n][k][prevBlack] = (canBeBlack && solve(n+v[k], k+1, true));
    }
 
    return dp[n][k][prevBlack] = (solve(n+1, k, false) || (canBeBlack && solve(n+v[k], k+1, true)));
}
 
bool checkPos(ll i, char c){
    for (ll k =0; k<=N; k++){
        for (ll j =0; j<=N; j++){
            dp[k][j][0] = -1;
            dp[k][j][1] = -1;
        }
    }
    s[i] = c;

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

    bool x = solve(0, 0, false);
    s[i] = '.';
    return x;
}
 
string solve_puzzle(string st, vi arr) {
    v = arr;
    s = st;
    ll n = sz(s);
    ll k = sz(v);
 
    string ans;
    ans.resize(n);
    for (ll i =0; i<n; i++){
        if (s[i] == '_' || s[i] == 'X'){
            ans[i] = s[i];
            continue;
        }
 
        bool w = checkPos(i,'_');
        bool b = checkPos(i,'X');
 
        if (w && b) ans[i] = '?';
        else if (w) ans[i] = '_';
        else ans[i] = 'X';
 
 
        // cout<<endl<<endl;
    }
 
    return ans;
}
 
/*
..........
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:45:49: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   45 |     if (s[n] == '_') return dp[n][k][prevBlack] = solve(n+1, k, false);
      |                             ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
paint.cpp:52:36: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   52 |         return dp[n][k][prevBlack] = (canBeBlack && solve(n+v[k], k+1, true));
      |                ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
paint.cpp:55:32: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   55 |     return dp[n][k][prevBlack] = (solve(n+1, k, false) || (canBeBlack && solve(n+v[k], k+1, true)));
      |            ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
paint.cpp: In function 'std::string solve_puzzle(std::string, vi)':
paint.cpp:82:8: warning: unused variable 'k' [-Wunused-variable]
   82 |     ll k = sz(v);
      |        ^
paint.cpp: In function 'bool checkPos(int, char)':
paint.cpp:61:25: warning: iteration 102 invokes undefined behavior [-Waggressive-loop-optimizations]
   61 |             dp[k][j][0] = -1;
      |             ~~~~~~~~~~~~^~~~
paint.cpp:60:24: note: within this loop
   60 |         for (ll j =0; j<=N; j++){
      |                        ^

• Subtask 1: 0 / 7
• Subtask 2: 0 / 3
• Subtask 3: 0 / 22
• Subtask 4: 0 / 27
• Subtask 5: 0 / 21
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10