Submission #697302

#	Time	Username	Problem	Language	Result	Execution time	Memory
697302		Dan4Life	The short shank; Redemption (BOI21_prison)	C++17	35 / 100	205 ms	524288 KiB

prison

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define int long long 
#define sz(a) (int)a.size()
#define all(a) a.begin(),a.end()
const int mxN = (int)1e5+10;
const int LINF = (int)1e18;
int n, k, T, a[mxN];
vector<vector<int>> dp,calc;

void dnc(int l, int r, int optl, int optr, int i) {
    if (l > r) return;
    int mid = (l+r)/2;
    pair<int,int> best = {LINF, 1};
    for (int k = optl; k <= min(mid, optr); k++) 
        best = min(best, {dp[k-1][i]+calc[k][mid],k});
    dp[mid][i+1] = best.fi;
    dnc(l,mid-1,optl,best.se,i);
    dnc(mid+1,r,best.se,optr,i);
}

int32_t main() {
    ios_base::sync_with_stdio(false); cin.tie(0);
    cin >> n >> k >> T; k++;
    calc.resize(n+2,vector<int>(n+2,0));
    dp.resize(n+2,vector<int>(k+2,LINF));
    for(int i = 1; i <= n; i++) cin >> a[i];
    for(int i = 1; i <= n; i++){
        int ans = 0, mn = a[i];
        for(int j = i; j <= n; j++)
            mn = min(mn+1, a[j]), ans+=(mn<=T), calc[i][j] = ans;
    }
    for(int i = 1; i <= n; i++) dp[i][1] = calc[1][i];
    for(int i = 1; i < k; i++) dnc(1,n,1,n,i);
    cout << dp[n][k];
}

• Subtask 1: 15 / 15
• Subtask 2: 0 / 10
• Subtask 3: 20 / 20
• Subtask 4: 0 / 10
• Subtask 5: 0 / 25
• Subtask 6: 0 / 20