Submission #612546

#	Time	Username	Problem	Language	Result	Execution time	Memory
612546		tengiz05	Homecoming (BOI18_homecoming)	C++17	100 / 100	193 ms	141600 KiB

homecoming

#include <bits/stdc++.h>

using i64 = long long;
using namespace std;

i64 solve(int n, int k, int *A, int *B) {
    vector<int> a(n), b(2 * n);
    for (int i = 0; i < n; i++) {
        a[i] = A[i];
        b[i] = B[i];
        b[i + n] = b[i];
    }
    i64 ans = accumulate(A, A + n, 0LL) - accumulate(B, B + n, 0LL);
    for (int i = 0; i < 1; i++) {
        vector<i64> pre(2 * n + 1);
        for (int i = 0; i < 2 * n; i++) {
            pre[i + 1] = pre[i] + b[i];
        }
        {
            vector<i64> dp(n), keep(n);
            keep[0] = a[0] - pre[k];
            dp[0] = 0LL;
            for (int i = 1; i < n; i++) {
                keep[i] = max(dp[i - 1] + a[i] - (pre[i + k] - pre[i]), keep[i - 1] + a[i] - b[i + k - 1]);
                dp[i] = max(dp[i - 1], keep[i]);
            }
            ans = max(ans, dp[n - 1]);
        } {
            vector<i64> dp(n), keep(n);
            keep[0] = a[0] - pre[k];
            dp[0] = keep[0];
            for (int i = 1; i < n; i++) {
                keep[i] = max(dp[i - 1] + a[i] - (pre[min(n, i + k)] - pre[i]), keep[i - 1] + a[i] - (i + k <= n ? b[i + k - 1] : 0));
                dp[i] = max(dp[i - 1], keep[i]);
            }
            ans = max(ans, dp[n - 1]);
        }
    }
    
    return ans;
}

/*

1
3 2
40 80 100
140 0 20


*/
long long solve(int N, int K, int *A, int *B);

#ifndef EVAL

int main() {
  int T; assert(scanf("%d", &T) == 1);
  for(int t = 0; t < T; t++) {
    int N, K; assert(scanf("%d%d", &N, &K) == 2);
    int *A = new int[N];
    int *B = new int[N];
    for(int i = 0; i < N; i++) assert(scanf("%d", &A[i]) == 1);
    for(int i = 0; i < N; i++) assert(scanf("%d", &B[i]) == 1);
    printf("%lld\n", solve(N, K, A, B));
    delete[] A;
    delete[] B;
  }
  return 0;
}
#endif

• Subtask 1: 13 / 13
• Subtask 2: 18 / 18
• Subtask 3: 31 / 31
• Subtask 4: 38 / 38