| # | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 338403 | 2020-12-23T05:25:02 Z | couplefire | Homecoming (BOI18_homecoming) | C++17 | 0 ms | 0 KB |
#include "homecoming.h"
#include <bits/stdc++.h>
using namespace std;
#define INF 1000000000000000009ll
long long solve(int n, int k, vector<int> arr, vector<int> brr){
for(int i = 0; i<n; i++) arr.push_back(arr[i]);
for(int i = 0; i<n; i++) brr.push_back(brr[i]);
long long cursum = 0;
deque<pair<long long, int>> dq;
long long sum = 0;
for(int i = 0; i<n; i++) sum += arr[i]-brr[i];
if(k == n){
return sum;
}
for(int i = n; i<n+n-k-1; i++){
cursum += arr[i]-brr[i];
if(dq.empty() || dq.front().first > cursum) dq.push_front({cursum, i});
}
long long minLen[n];
long long shift = 0;
for(int i = n-1; i>=0; i--){
while(!dq.empty() && dq.front().second >= i+n-k) dq.pop_front();
shift += arr[i]-brr[i];
while(!dq.empty() && dq.back().first >= arr[i]-brr[i]-shift) dq.pop_back();
dq.push_back({arr[i]-brr[i]-shift, i});
minLen[i%n] = dq.front().first+shift;
}
// cout << minLen[0] << endl;
cursum = 0;
for(int i = 0; i<k-1; i++) cursum += arr[i];
int badpos = -1;
for(int i = k-1; i<=n+k; i++){
if(minLen[i%n]+cursum < 0){
badpos = i%n; break;
}
cursum -= arr[i-k+1];
cursum += arr[i];
}
if(badpos == -1){
// cout << "HI" << endl;
return sum;
}
// cout << badpos << endl;
for(int i = 0; i<n; i++) arr[i] = arr[i+badpos];
for(int i = 0; i<n; i++) brr[i] = brr[i+badpos];
while(arr.size() > n) arr.pop_back();
while(brr.size() > n) brr.pop_back();
cursum = 0;
long long prefix[n];
for(int i = 0; i<n; i++) cursum += brr[i], prefix[i] = cursum;
long long dp[n][2];
dp[0][0] = 0;
dp[0][1] = -INF;
if(k == 1) dp[0][1] = arr[0]-brr[0];
for(int i = 1; i<n; i++){
dp[i][0] = 0, dp[i][1] = -INF;
dp[i][0] += max(dp[i-1][0], dp[i-1][1]);
if(i == k-1) dp[i][1] = arr[0]-prefix[i];
else if(i > k-1) dp[i][1] = max(dp[i-1][1]+arr[i-k+1]-brr[i], dp[i-k][0]-prefix[i]+prefix[i-k]+arr[i-k+1]);
}
// cout << dp[2][1] << endl;
return max(dp[n-1][0], dp[n-1][1]);
}