oj.uz

Submission #21050

# Submission time Handle Problem Language Result Execution time Memory
21050 2017-04-04T05:21:00 Z sbansalcs Watching (JOI13_watching) C++14
50 / 100
 1000 ms 17676 KB 
#include <iostream>
#include <algorithm>
using namespace std;
typedef long long ll;
const int N = 2001;
ll arr[N];
int dp[N][N];
int n,p,q;

bool check(ll w)   {
    for (int i=n+1; i>=1; i--) {
        for (int j=0; j<=q; j++) {
            if(i==n+1)  dp[i][j]=0;
            else    {
                ll a;
                a=arr[i]+w;
                int lx=i+1,rx=n+1,mx;
                while (lx<rx) {
                    mx= (lx+rx)/2;
                    if(arr[mx]>=a)  rx=mx;
                    else    lx=mx+1;
                }
                dp[i][j]=1+dp[lx][j];
                if(j!=0)    {
                    a=arr[i]+2*w;
                    int lx=i+1,rx=n+1,mx;
                    while (lx<rx) {
                        mx= (lx+rx)/2;
                        if(arr[mx]>=a)  rx=mx;
                        else    lx=mx+1;
                    }
                    dp[i][j]=min(dp[i][j],dp[lx][j-1]);
                    dp[i][j]=min(dp[i][j],dp[i][j-1]);
                }
            }
        }
    }
    return dp[1][q]<=p;
}

int main() {
    scanf("%d %d %d",&n,&p,&q);
    for (int i=1; i<=n; i++) {
        scanf("%lld",arr+i);
    }
    if(p+q>=n)  {
        cout<<1<<endl;return 0;
    }
    sort(arr+1,arr+1+n);
    arr[n+1]=2e9;
    int lx=1,rx=1e9,mx;
    while (lx<rx) {
        mx=(lx+rx)/2;
        if(check(mx))   rx=mx;
        else    lx=mx+1;
    }
    cout<<lx<<endl;
    return 0;
}

Compilation message

watching.cpp: In function 'int main()':
watching.cpp:42:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d %d",&n,&p,&q);
                               ^
watching.cpp:44:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld",arr+i);
                            ^

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 17676 KB Output is correct
2 Correct 0 ms 17676 KB Output is correct
3 Correct 0 ms 17676 KB Output is correct
4 Correct 0 ms 17676 KB Output is correct
5 Correct 0 ms 17676 KB Output is correct
6 Correct 0 ms 17676 KB Output is correct
7 Correct 0 ms 17676 KB Output is correct
8 Correct 0 ms 17676 KB Output is correct
9 Correct 0 ms 17676 KB Output is correct
10 Correct 3 ms 17676 KB Output is correct
11 Correct 0 ms 17676 KB Output is correct
12 Correct 3 ms 17676 KB Output is correct
13 Correct 0 ms 17676 KB Output is correct
14 Correct 0 ms 17676 KB Output is correct
15 Correct 0 ms 17676 KB Output is correct

Subtask #2
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 17676 KB Output is correct
2 Correct 0 ms 17676 KB Output is correct
3 Correct 0 ms 17676 KB Output is correct
4 Correct 0 ms 17676 KB Output is correct
5 Correct 0 ms 17676 KB Output is correct
6 Correct 0 ms 17676 KB Output is correct
7 Correct 46 ms 17676 KB Output is correct
8 Execution timed out 1000 ms 17676 KB Execution timed out
9 Halted 0 ms 0 KB -