Submission #601032

#	Time	Username	Problem	Language	Result	Execution time	Memory
601032		HediChehaidar	Paint By Numbers (IOI16_paint)	C++17	100 / 100	975 ms	377708 KiB

paint

#include<bits/stdc++.h>
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef double db;
ll gcd(ll a , ll b) {return b ? gcd(b , a % b) : a ;} // greatest common divisor (PGCD)
ll lcm(ll a , ll b) {return (a * b) / gcd(a , b);} // least common multiple (PPCM)
#define ss second
#define ff first
#define all(x) (x).begin() , (x).end()
#define pb push_back
#define vi vector<int>
#define vii vector<pair<int,int>>
#define vl vector<ll>
#define vll vector<pair<ll,ll>>
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pdd  pair<double,double>
#define vdd  vector<pdd>
#define dte  tuple<double , double , double>
using namespace std;
const int INF = 1000*1000*1000; // 1 e 9
const int MOD = 1e9 + 7;//998244353 ;
const double EPS = 0.000000001; // 1 e -9
const ll inf = (ll)1e18;


int k , n;
string s;
int nb[(int)2e5 + 10];
int cnt[(int)2e5 + 10];
bool dp[(int)2e5 + 10][101];
bool vis[(int)2e5 + 10][101];
vi le[2][(int)2e5 + 10];
bool ok[2][(int)2e5 + 10];
void update(int a , int l , int r , int i , int j , int p){
    le[p][i].pb(j);
}
vi len;
bool solve(int pos , int cur){
    //cout << pos << " " << cur << endl;
    if(pos >= n)return cur == k;
    if(cur == k) {
        if(cnt[n] - cnt[pos] == 0){
            update(0 , 0 , n - 1 , pos , n - 1 , 1);
            return true;
        }
        return false;
    }
    if(vis[pos][cur]) return dp[pos][cur];
    vis[pos][cur] = true;
    if(s[pos] != '.'){
        if(s[pos] == '_') return dp[pos][cur] = solve(pos + 1 , cur);
        else {
            bool ans = (n >= pos + len[cur]) && (nb[pos + len[cur]] - nb[pos] == 0) && !(n > pos + len[cur] && s[pos + len[cur]] == 'X') && solve(pos + len[cur] + 1, cur + 1);
            if(ans){
                update(0 , 0 , n -1 , pos , pos + len[cur] - 1 , 0);
                if(n > pos + len[cur])  update(0 , 0 , n- 1 , pos + len[cur]  , pos + len[cur], 1);
            }
            return dp[pos][cur] = ans;
        }
    }
    bool a = solve(pos + 1 , cur);
    bool ans = (n >= pos + len[cur]) && (nb[pos + len[cur]] - nb[pos] == 0) && !(n > pos + len[cur] && s[pos + len[cur]] == 'X') && solve(pos + len[cur] + 1, cur + 1);
    if(ans){
        update(0 , 0 , n -1 , pos , pos + len[cur] - 1 , 0);
        if(n > pos + len[cur]) update(0 , 0 , n- 1 , pos + len[cur] , pos + len[cur] , 1);
    }
    if(a) update(0 , 0 , n - 1 , pos , pos , 1);
    //cout << pos << " " << cur << " " << a << " " << ans << endl;
    return dp[pos][cur] = a || ans;
}
string solve_puzzle(string w, vi c){
    k = c.size(); s = w; n = s.length(); len = c;
    for(int i = 1 ; i <= n ; i++) nb[i] = nb[i - 1] + (s[i - 1] == '_');
    for(int i = 1 ; i <= n ; i++) cnt[i] = cnt[i - 1] + (s[i - 1] == 'X');
    //for(auto e : len) cout << e << " "; cout << endl;
    solve(0 , 0);
    int idx = 0;
    for(int j = 0 ; j < 2 ; j++){
        idx = 0;
        for(int i = 0 ; i < n ; i++){
            if(le[j][i].empty()) continue;
            if(idx < i) idx = i;
            for(auto e : le[j][i]){
                while(idx <= e){
                    //cout << e << " " << idx << endl;
                    ok[j][idx] = true; idx++;
                }
            }
        }
    }
    for(int i = 0 ; i < n ; i++){
        if(s[i] != '.') continue;
        bool b = ok[1][i];
        bool a = ok[0][i];
        if(a && b) s[i] = '?';
        else if(a) s[i] = 'X';
        else{
            assert(b);
            s[i] = '_';
        }
    }
    return s;
}
/*int main(){
    //ifstream fin ("testing.txt");
    //ofstream fout ("output.txt");
    ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    string w; cin>>w;
    int kk; cin>>kk;
    vi c(kk); for(int i = 0 ; i < kk ; i++) cin>>c[i];
    cout << solve_puzzle(w , c);
    return 0;
}
*/
/*
    Think of : BS / DFS / BFS / SSSP / SCC / MSP / MAX FLOW / TOPSORT / LCA / MATRIX / DP(bitmask) / 2 POINTERS / SEG TREE / MATH / UN FIND / MO / HLD
    Read the statement CAREFULLY !!
    Make a GREADY APPROACH !!!! (start from highest / lowest)
    Make your own TESTS !!
    Be careful from CORNER CASES !
*/

• 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