Submission #737714

#	Time	Username	Problem	Language	Result	Execution time	Memory
737714		Abrar_Al_Samit	Painting Walls (APIO20_paint)	C++17	63 / 100	1596 ms	409432 KiB

paint

#include "paint.h"
#include <bits/stdc++.h>
using namespace std;
 
const int nax = 1e5 + 1;
 
 
vector<int> col_to_wall[nax], cand[nax];
bool good[nax];
int dp[2][1000];
 
int minimumInstructions(
    int N, int M, int K, vector<int> C,
    vector<int> A, vector<vector<int>> B) {
 
    
    for(int i=0; i<N; ++i) {
        col_to_wall[C[i]].push_back(i);
    }
 
    for(int i=0; i<M; ++i) {
        for(int j=0; j<A[i]; ++j) {
            for(int x : col_to_wall[B[i][j]]) {
                cand[x].push_back(i);
            }
        }
    }
    for(int i=0; i<K; ++i) {
        col_to_wall[i].clear();
    }

    int rw = 0;
    for(int i=N-1; i>=1; --i, rw = 1-rw) {

        int ptr = 0;
        for(int j=0; j<cand[i-1].size(); ++j) {
            dp[rw][j] = 0;

            if(cand[i-1][j]+1==M) {
                if(!cand[i].empty() && cand[i][0]==0) {
                    dp[rw][j] = 1 + dp[1-rw][0];
                }
                continue;
            }
 
            while(ptr+1<cand[i].size() && cand[i][ptr+1]<=cand[i-1][j]+1) {
                ++ptr;
            }
            if(!cand[i].empty() && cand[i][ptr]==cand[i-1][j]+1) {
                dp[rw][j] = 1 + dp[1-rw][ptr];
            }
        }

        if(i-1<=N-M) {
            for(int j=0; j<cand[i-1].size(); ++j) {
                int cur = 1 + dp[rw][j];
                if(cur>=M) good[i-1] = 1;
            }
        }
    }
    if(M==1 && !cand[N-1].empty()) good[N-1] = 1;
 
    if(!good[0]) return -1;
    int last = 0, pending = -1;
 
    int ans = 1;
    for(int i=1; i<N; ++i) {
        if(good[i]) {
            pending = i;
        }
        if(last+M==i) {
            if(pending==-1) return -1;
            last = pending;
            pending = -1;
            ++ans;
        }
    }
    return ans;
}

Compilation message (stderr)

paint.cpp: In function 'int minimumInstructions(int, int, int, std::vector<int>, std::vector<int>, std::vector<std::vector<int> >)':
paint.cpp:36:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |         for(int j=0; j<cand[i-1].size(); ++j) {
      |                      ~^~~~~~~~~~~~~~~~~
paint.cpp:46:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |             while(ptr+1<cand[i].size() && cand[i][ptr+1]<=cand[i-1][j]+1) {
      |                   ~~~~~^~~~~~~~~~~~~~~
paint.cpp:55:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |             for(int j=0; j<cand[i-1].size(); ++j) {
      |                          ~^~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 15 / 15
• Subtask 3: 13 / 13
• Subtask 4: 23 / 23
• Subtask 5: 0 / 37