oj.uz

Submission #155063

# Submission time Handle Problem Language Result Execution time Memory
155063 2019-09-26T05:23:18 Z Charis02 Homecoming (BOI18_homecoming) C++14
62 / 100
 237 ms 133812 KB 
#include<iostream>
#define ll long long
#define rep(i,a,b) for(int i = a;i < b;i++)
#define N 2000003
#define INF 1e12

using namespace std;

ll books[N],prize[N],sum[N],n,k;
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 NN,int K,int A[],int B[])
{
    n = NN;
    k = K;
    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;
}

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 2 ms 376 KB Output is correct

Subtask #2
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 3 ms 760 KB Output is correct
7 Correct 3 ms 748 KB Output is correct
8 Correct 2 ms 504 KB Output is correct
9 Correct 3 ms 632 KB Output is correct
10 Correct 3 ms 508 KB Output is correct

Subtask #3
31.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 60 ms 25052 KB Output is correct
2 Correct 5 ms 888 KB Output is correct
3 Correct 237 ms 133812 KB Output is correct
4 Correct 4 ms 1528 KB Output is correct
5 Correct 13 ms 3536 KB Output is correct

Subtask #4
0 / 38.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 3 ms 760 KB Output is correct
7 Correct 3 ms 748 KB Output is correct
8 Correct 2 ms 504 KB Output is correct
9 Correct 3 ms 632 KB Output is correct
10 Correct 3 ms 508 KB Output is correct
11 Correct 60 ms 25052 KB Output is correct
12 Correct 5 ms 888 KB Output is correct
13 Correct 237 ms 133812 KB Output is correct
14 Correct 4 ms 1528 KB Output is correct
15 Correct 13 ms 3536 KB Output is correct
16 Correct 237 ms 133696 KB Output is correct
17 Correct 97 ms 29852 KB Output is correct
18 Incorrect 174 ms 42688 KB Output isn't correct
19 Halted 0 ms 0 KB -