Submission #627190

#	Time	Username	Problem	Language	Result	Execution time	Memory
627190		typ_ik	Catfish Farm (IOI22_fish)	C++17	3 / 100	82 ms	7268 KiB

fish

#include <bits/stdc++.h>

#define all(x) (x).begin(), (x).end()

using namespace std;

long long max_weights(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
    int block1 = 0;
    for (auto c : X) block1 += (c & 1 ^ 1);
    if (block1 == M)
        return accumulate(all(W), 0ll);

    long long val[N + 1];
    for (int i = 0; i <= N; i++)
        val[i] = 0;
    for (int i = 0; i < M; i++)
        val[X[i]] = W[i];

    long long evenPref[N + 1], evenSuf[N + 1];
    long long oddPref[N + 1], oddSuf[N + 1];

    for (int i = 0; i <= N; i++)
        evenPref[i] = evenSuf[i] = oddPref[i] = oddSuf[i] = 0;

    evenPref[0] = val[0];
    evenSuf[N - 1] = ((N - 1) & 1 ^ 1) * val[N - 1];

    for (int i = 1; i < N; i++) {
        evenPref[i] = evenPref[i - 1];
        if (i & 1 ^ 1) evenPref[i] += val[i];
    }

    for (int i = N - 2; i >= 0; i--) {
        evenSuf[i] = evenSuf[i + 1];
        if (i & 1 ^ 1) evenSuf[i] += val[i];
    }

    for (int i = 1; i < N; i++) {
        oddPref[i] = oddPref[i - 1];
        if (i & 1) oddPref[i] += val[i];
    }

    oddSuf[N - 1] = ((N - 1) & 1) * val[N - 1];
    for (int i = N - 2; i >= 0; i--) {
        oddSuf[i] = oddSuf[i + 1];
        if (i & 1) oddSuf[i] += val[i];
    }

    long long ans = max(evenPref[N - 1], oddPref[N - 1]);

    for (int i = 0; i < N; i++) {
        long long lEven = (i ? evenPref[i - 1] : 0);
        long long rOdd = oddSuf[i + 1];
        ans = max(ans, lEven + rOdd);
        long long lOdd = (i ? oddPref[i - 1] : 0);
        long long rEven = evenSuf[i + 1];
        ans = max(ans, lOdd + rEven);
    }

    return ans;
}

//main() {
//    int N = 10, M = 4;
//    vector <int> X = {0, 5, 7, 4};
//    vector <int> Y = {0, 0, 0, 0};
//    vector <int> W = {10, 5, 3, 6};
//    cout << max_weights(N, M, X, Y, W) << '\n';
//}

Compilation message (stderr)

fish.cpp: In function 'long long int max_weights(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
fish.cpp:9:35: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
    9 |     for (auto c : X) block1 += (c & 1 ^ 1);
      |                                 ~~^~~
fish.cpp:26:31: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   26 |     evenSuf[N - 1] = ((N - 1) & 1 ^ 1) * val[N - 1];
      |                       ~~~~~~~~^~~
fish.cpp:30:15: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   30 |         if (i & 1 ^ 1) evenPref[i] += val[i];
      |             ~~^~~
fish.cpp:35:15: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   35 |         if (i & 1 ^ 1) evenSuf[i] += val[i];
      |             ~~^~~

• Subtask 1: 3 / 3
• Subtask 2: 0 / 6
• Subtask 3: 0 / 9
• Subtask 4: 0 / 14
• Subtask 5: 0 / 21
• Subtask 6: 0 / 17
• Subtask 7: 0 / 14
• Subtask 8: 0 / 16