Submission #438789

#	Time	Username	Problem	Language	Result	Execution time	Memory
438789		MilosMilutinovic	Watching (JOI13_watching)	C++14	100 / 100	286 ms	16840 KiB

watching

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

const int N=2050;

int n,p,q,a[N],dp[N][N];
bool Check(int w){
    memset(dp,1e9,sizeof dp);
    dp[0][0]=0;
    int x=0,y=0;
    for(int i=1;i<=n;i++){
        while(a[i]-a[x+1]>=w)x++;
        while(a[i]-a[y+1]>=2*w)y++;
        for(int j=0;j<=n;j++){
            dp[i][j]=dp[x][j]+1;
            if(j>0)dp[i][j]=min(dp[i][j],dp[y][j-1]);
        }
    }
    for(int j=0;j<=min(n,q);j++){
        if(dp[n][j]<=p)return true;
    }
    return false;
}

int main(){
    scanf("%i %i %i",&n,&p,&q);
    for(int i=1;i<=n;i++)scanf("%i",&a[i]);
    sort(a+1,a+n+1);
    int bot=1,top=1e9,ans=1e9;
    while(bot<=top){
        int mid=bot+top>>1;
        if(Check(mid))ans=mid,top=mid-1;
        else bot=mid+1;
    }
    printf("%i",ans);
    return 0;
}

Compilation message (stderr)

watching.cpp: In function 'int main()':
watching.cpp:31:20: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   31 |         int mid=bot+top>>1;
      |                 ~~~^~~~
watching.cpp:26:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |     scanf("%i %i %i",&n,&p,&q);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~
watching.cpp:27:31: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |     for(int i=1;i<=n;i++)scanf("%i",&a[i]);
      |                          ~~~~~^~~~~~~~~~~~

• Subtask 1: 50 / 50
• Subtask 2: 50 / 50