Submission #96925

#	Time	Username	Problem	Language	Result	Execution time	Memory
96925		liwi	Paint By Numbers (IOI16_paint)	C++11	90 / 100	2049 ms	62896 KiB

paint

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
typedef tree<pair<int,int>, null_type, less<pair<int,int>>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;

#define scan(x) do{while((x=getchar())<'0'); for(x-='0'; '0'<=(_=getchar()); x=(x<<3)+(x<<1)+_-'0');}while(0)
char _;
#define complete_unique(a) a.erase(unique(a.begin(),a.end()),a.end())
#define all(a) a.begin(),a.end()
#define println printf("\n");
#define readln(x) getline(cin,x);
#define pb push_back
#define endl "\n"
#define INT_INF 0x3f3f3f3f
#define LL_INF 0x3f3f3f3f3f3f3f3f
#define MOD 1000000007
#define mp make_pair
#define fastio cin.tie(0); cin.sync_with_stdio(0);

#define MAXN 200005
#define MAXK 101

typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
typedef unordered_map<int,int> umii;
typedef pair<int,int> pii;
typedef pair<double,double> pdd;
typedef pair<ll,ll> pll;
typedef pair<int,pii> triple;
typedef int8_t byte;

mt19937 g1;

int randint(int a, int b){return uniform_int_distribution<int>(a, b)(g1);}
ll randlong(ll a,ll b){return uniform_int_distribution<long long>(a, b)(g1);}

ll gcd(ll a, ll b){return b == 0 ? a : gcd(b, a % b);}
ll lcm(ll a, ll b){return a*b/gcd(a,b);}
ll fpow(ll  b, ll exp, ll mod){if(exp == 0) return 1;ll t = fpow(b,exp/2,mod);if(exp&1) return t*t%mod*b%mod;return t*t%mod;}
ll divmod(ll i, ll j, ll mod){i%=mod,j%=mod;return i*fpow(j,mod-2,mod)%mod;}

int len,psa[MAXN],need[MAXN];
string res;
bool forw[MAXN][MAXK],backw[MAXN][MAXK],white[MAXN],eforr[MAXN][MAXK],done[MAXK][MAXN];
bitset<MAXN> blocks[MAXK],possible;

string solve_puzzle(string s, vector<int> c){
  	int K = (int)c.size();
    len = (int)s.size();
    for(int i=1; i<=len; i++){
        psa[i] = psa[i-1]+(s[i-1]=='X'||s[i-1]=='.');
        need[i] = need[i-1]+(s[i-1]=='X');
    }
    for(int i=1; i<=K; i++)
        for(int k=1; k<=c[i-1]; k++)
            blocks[i][k] = true;
    forw[0][0] = backw[len+1][0] = true;
    for(int i=1; i<=len; i++){
        forw[i][0] = need[i]==0;
        for(int k=1; k<=K; k++){
            if(!(i == c[k-1] && k == 1) && i-c[k-1]-1 < 0) continue;
            int cur_len = c[k-1], valid = (psa[i]-psa[i-cur_len])==cur_len;
            if(s[i-1] != 'X') forw[i][k] = forw[i-1][k];
            if(valid && ((k == 1 && need[i-cur_len] == 0) || (k != 1 && i > cur_len && s[i-cur_len-1] != 'X' && forw[i-cur_len-1][k-1])))
                forw[i][k] = eforr[i][k] = true;
        }
    }
    for(int i=len; i>=1; i--){
        backw[i][0] = need[len]-need[i-1]==0;
        for(int k=1; k<=K; k++){
            if(!(i+c[K-k]-1 <= len && k == 1) && i+c[K-k]+1 > len) continue;
            int idx = K-k+1, cur_len = c[idx-1], valid = (psa[i+cur_len-1]-psa[i-1])==cur_len;
            if(s[i-1] != 'X') backw[i][k] = backw[i+1][k];
            if(valid && ((k == 1 && (i+cur_len > len || need[len]-need[i+cur_len-1] == 0)) || (k != 1 && len-i+1 > cur_len && s[i+cur_len-1] != 'X' && backw[i+cur_len+1][k-1]))){
                backw[i][k] = true;
                if(i >= 2 && s[i-2] != 'X' && forw[i-2][K-k] && !done[idx][i-1]){
                    done[idx][i-1] = true;
                    possible|=(blocks[idx]<<(i-1));
                }
            }
        }
    }
    for(int i=1; i<=len; i++)
        for(int k=1; k<=K;k ++)
            if(eforr[i][k] && ((i==len && k == K) || (s[i] != 'X' && backw[i+2][K-k])) && !done[k][i-c[k-1]]){
                done[k][i-c[k-1]] = true;
                possible|=(blocks[k]<<(i-c[k-1]));
            }
    for(int i=1; i<=len; i++){
        for(int k=0; k<=K; k++){
            bool can_white = s[i-1]!='X'&&forw[i-1][k]&&backw[i+1][K-k];
            if(k == 0) can_white = s[i-1]!='X'&&(need[i-1]==0)&&backw[i+1][K];
            else if(k == K) can_white = s[i-1]!='X'&&forw[i-1][k]&&(need[len]-need[i-1]==0);
            if(can_white){
                white[i] = true;
                break;
            }
        }
    }
    for(int i=1; i<=len; i++){
        if(possible[i] && white[i]) res+="?";
        else if(possible[i]) res+="X";
        else res+="_";
    }
    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