Submission #866945

#	Time	Username	Problem	Language	Result	Execution time	Memory
866945		HossamHero7	The short shank; Redemption (BOI21_prison)	C++14	35 / 100	2082 ms	129112 KiB

prison

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define endl '\n'
int dp[4005][2];
int cost[4005][4005];
void calc(int l,int r,int opt1,int opt2,int k){
    if(l > r) return;
    int i = l + r >> 1;
    pair<int,int> opt{1e9,-1};
    for(int p=opt1;p<=min(opt2,r);p++){
        if(p) opt = min(opt,{dp[p-1][k-1&1]+cost[p][i],p});
        else opt = min(opt,{cost[0][i],p});
    }
    dp[i][k&1] = opt.first;
    calc(l,i-1,opt1,opt.second,k);
    calc(i+1,r,opt.second,opt2,k);
}
void solve(){
    int n,d,t;
    cin>>n>>d>>t;
    vector<int> v(n);
    for(auto &i:v) cin>>i;
    for(int i=0;i<n;i++){
        int lst = v[i];
        cost[i][i] = (lst <= t);
        for(int j=i+1;j<n;j++) {
            cost[i][j] += cost[i][j-1];
            if(v[j] > lst) lst ++;
            else lst = v[j];
            cost[i][j] += (lst <= t);
        }
    }
    for(int i=0;i<n;i++) dp[i][0] = cost[0][i];
    for(int k=1;k<=d;k++){
        calc(0,n-1,0,n-1,k);
    }
    cout<<dp[n-1][d&1]<<endl;
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);      cout.tie(0);
    int t=1;
    //cin>>t;
    while(t--){
        solve();
    }
    return 0;
}

Compilation message (stderr)

prison.cpp: In function 'void calc(int, int, int, int, int)':
prison.cpp:9:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
    9 |     int i = l + r >> 1;
      |             ~~^~~
prison.cpp:12:39: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   12 |         if(p) opt = min(opt,{dp[p-1][k-1&1]+cost[p][i],p});
      |                                      ~^~

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