Submission #87312

#	Time	Username	Problem	Language	Result	Execution time	Memory
87312		7Polygonz	K blocks (IZhO14_blocks)	C++11	100 / 100	426 ms	43324 KiB

blocks

using namespace std ;
#include <bits/stdc++.h> /* #7th-Polygon */
typedef pair < int , int > IntInt ;

const int N = 1e5 + 7 ;
const int K = 100 + 7 ;

unsigned int n , k , a[N] , dp[N][K] ;

int main()
{
    ios::sync_with_stdio(false) ;
    cout.tie(nullptr) ;
    cin.tie(nullptr) ;

    cin >> n >> k ;
    for (int i = 1 ; i <= n ; ++i)
        cin >> a[i] ;

    memset(dp , -1 , sizeof(dp)) ;

    dp[0][1] = 0 ;
    for (int i = 1 ; i <= n ; ++i)
        dp[i][1] = max(dp[i - 1][1] , a[i]) ;

    for (int b = 2 ; b <= k ; ++b)
    {
        stack < IntInt > my_stack ;
        for (int i = b ; i <= n ; ++i)
        {
            int min_dp = dp[i - 1][b - 1] ;
            for ( ; my_stack.size() ; my_stack.pop())
            {
                if (a[my_stack.top().first] > a[i]) break ;
                min_dp = min(min_dp , my_stack.top().second) ;
            }

            dp[i][b] = min(min_dp + a[i] , dp[my_stack.size() ? my_stack.top().first : 0][b]) ;
            my_stack.emplace(i , min_dp) ;
        }
    }

    cout << dp[n][k] << "\n" ;
    return 0 ;
}

Compilation message (stderr)

blocks.cpp: In function 'int main()':
blocks.cpp:17:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 1 ; i <= n ; ++i)
                      ~~^~~~
blocks.cpp:23:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 1 ; i <= n ; ++i)
                      ~~^~~~
blocks.cpp:26:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int b = 2 ; b <= k ; ++b)
                      ~~^~~~
blocks.cpp:29:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i = b ; i <= n ; ++i)
                          ~~^~~~

• Subtask 1: 14 / 14
• Subtask 2: 18 / 18
• Subtask 3: 21 / 21
• Subtask 4: 47 / 47