Submission #560346

#	Time	Username	Problem	Language	Result	Execution time	Memory
560346		piOOE	Painting Walls (APIO20_paint)	C++17	100 / 100	686 ms	14548 KiB

paint

#include "paint.h"

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

vector<int> dp[2], g[100000];

int minimumInstructions(int N, int M, int K, vector<int> C, vector<int> A, vector<vector<int>> B) {
    for (int i = 0; i < M; ++i) {
        for (int x: B[i]) {
            g[x].push_back(i);
        }
    }
    vector<bool> ok(N);
    vector<int> was(M, -1);
    for (int i = N - 1; i > -1; --i) {
        int nw = i & 1;
        int pr = nw ^ 1;
        dp[nw].resize(g[C[i]].size());
        for (int k = 0; k < dp[nw].size(); ++k) {
            int j = g[C[i]][k];
            if (was[(j + 1) % M] != -1) {
                int it = was[(j + 1) % M];
                dp[nw][k] = min(M, 1 + dp[pr][it]);
            } else {
                dp[nw][k] = 1;
            }
            if (dp[nw][k] == M) {
                ok[i] = true;
            }
        }
        if (i != N - 1) {
            for (int j : g[C[i + 1]])
                was[j] = -1;
        }
        int pp = 0;
        for (int j : g[C[i]]) {
            was[j] = pp++;
        }
    }
    int lst = N, p = N;
    int ans = 0;
    for (int i = N - M; i > -1; --i) {
        if (i + M < p) {
            if (lst >= p) {
                return -1;
            }
            p = lst;
            ++ans;
        }
        if (ok[i]) {
            lst = i;
        }
    }
    if (p != 0) {
        if (lst >= p) return -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:23:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |         for (int k = 0; k < dp[nw].size(); ++k) {
      |                         ~~^~~~~~~~~~~~~~~

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