oj.uz

Submission #155060

# Submission time Handle Problem Language Result Execution time Memory
155060 2019-09-26T05:22:05 Z Charis02 Homecoming (BOI18_homecoming) C++14
0 / 100
 47 ms 22704 KB 
#include<iostream>
#define ll int
#define rep(i,a,b) for(int i = a;i < b;i++)
#define N 200003
#define INF 1e12

using namespace std;

ll books[N],prize[N],sum[N];
ll dp[N][2];
const ll PASSED=1,NPASSED=0;

ll get_sum(ll i,ll j)
{
    if(i == 0)
        return sum[j];

    return sum[j] - sum[i-1];
}

ll solve(int n,int k,int A[],int B[])
{
    rep(i,0,n)
    {
        prize[i] = A[i];
        books[i] = B[i];

        if(i == 0)
            sum[i] = books[i];
        else
            sum[i] = sum[i-1]+books[i];
    }

    /*
        if you pass class i and class j and j-i < k it is optimal to pass all classes in between.
    */

    // fix that class 0 is passed

    dp[0][PASSED] = prize[0] - get_sum(0,k-1);
    dp[0][NPASSED] = -INF;

    rep(i,1,n)
    {
        ll nextbook = i+k-1;

        // passed previous class
        ll cur = dp[i-1][PASSED];
        if(nextbook < n)
            cur -= books[nextbook];
        cur+=prize[i];
        dp[i][PASSED] = cur;

        //didn't pass previous class
        cur = dp[i-1][NPASSED];
        cur -= get_sum(i,min(n-1,nextbook)); // if we add stuff that is already in dp[i-1][NPASSED], then optimal answer isn't here since we could just pass class i-1
        cur+=prize[i];
        dp[i][PASSED] = max(dp[i][PASSED],cur);

        dp[i][NPASSED] = max(dp[i-1][NPASSED],dp[i-1][PASSED]);
    }

    ll ans = max(dp[n-1][PASSED],dp[n-1][NPASSED]);

    // fix that he didn't pass class 0

    dp[0][NPASSED] = 0;
    dp[0][PASSED] = -INF;

    rep(i,1,n)
    {
        ll nextbook = (i+k-1)%n;

        // passed previous class
        ll cur = dp[i-1][PASSED];
        cur -= books[nextbook];
        cur+=prize[i];
        dp[i][PASSED] = cur;

        //didn't pass previous class
        cur = dp[i-1][NPASSED];
        if(nextbook < i)
            cur -= get_sum(i,n-1) + get_sum(0,nextbook);
        else
            cur -= get_sum(i,nextbook);

        cur+=prize[i];
        dp[i][PASSED] = max(dp[i][PASSED],cur);

        dp[i][NPASSED] = max(dp[i-1][NPASSED],dp[i-1][PASSED]);
    }

    ans = max(ans,dp[n-1][PASSED]);
    ans = max(ans,dp[n-1][NPASSED]);

    return ans;
}

Compilation message

homecoming.cpp: In function 'int solve(int, int, int*, int*)':
homecoming.cpp:5:13: warning: overflow in implicit constant conversion [-Woverflow]
 #define INF 1e12
             ^
homecoming.cpp:41:23: note: in expansion of macro 'INF'
     dp[0][NPASSED] = -INF;
                       ^~~
homecoming.cpp:5:13: warning: overflow in implicit constant conversion [-Woverflow]
 #define INF 1e12
             ^
homecoming.cpp:68:22: note: in expansion of macro 'INF'
     dp[0][PASSED] = -INF;
                      ^~~

Subtask #1
0 / 13.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 504 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 18.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 504 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 31.0

# Verdict Execution time Memory Grader output
1 Runtime error 47 ms 22704 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -

Subtask #4
0 / 38.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 504 KB Output isn't correct
2 Halted 0 ms 0 KB -