Submission #411590

#	Time	Username	Problem	Language	Result	Execution time	Memory
411590		nxteru	Paint By Numbers (IOI16_paint)	C++14	100 / 100	526 ms	44936 KiB

paint

#include "paint.h"
#include <bits/stdc++.h>
using namespace std;

bool dp[200005][105],dp2[200005][105];
int b[200005],w[200005],ims[200005];
string solve_puzzle(string s, vector<int> c) {
    s='_'+s;
    s+='_';
    int n=s.size(),k=c.size();
    for(int i=0;i<n;i++){
        if(s[i]=='X')b[i]++;
        if(i>0)b[i]+=b[i-1];
        if(s[i]=='_')w[i]++;
        if(i>0)w[i]+=w[i-1];
    }
    dp[0][0]=true;
    for(int i=0;i<n-1;i++){
        for(int j=0;j<=k;j++){
            if(!dp[i][j])continue;
            if(s[i+1]!='X')dp[i+1][j]=true;
            if(j<k&&i+c[j]<n-1&&w[i+c[j]]-w[i]==0&&s[i+c[j]+1]!='X')dp[i+c[j]+1][j+1]=true;
        }
    }
    dp2[n-1][k]=true;
    for(int i=n-1;i>0;i--){
        for(int j=k;j>=0;j--){
            if(!dp2[i][j])continue;
            if(s[i-1]!='X')dp2[i-1][j]=true;
            if(j>0&&i-c[j-1]>0&&w[i-1]-w[i-c[j-1]-1]==0&&s[i-c[j-1]-1]!='X')dp2[i-c[j-1]-1][j-1]=true;
        }
    }
    string ans;
    for(int i=0;i<n;i++)ans+='.';
    for(int i=0;i<n;i++){
        for(int j=0;j<=k;j++){
            if(dp[i][j]&&dp2[i][j])ans[i]='_';
        }
    }
    for(int i=0;i<n-1;i++){
        for(int j=0;j<=k;j++){
            if(!dp[i][j])continue;
            if(j<k&&i+c[j]<n-1&&w[i+c[j]]-w[i]==0&&s[i+c[j]+1]!='X'&&dp2[i+c[j]+1][j+1]){
                ims[i+1]++;
                ims[i+c[j]+1]--;
            }
        }
    }
    for(int i=0;i<n;i++){
        if(i>0)ims[i]+=ims[i-1];
        if(ims[i]>0){
            if(ans[i]=='_')ans[i]='?';
            else ans[i]='X';
        }
    }
    return ans.substr(1,n-2);
}

• 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