Submission #442932

#	Time	Username	Problem	Language	Result	Execution time	Memory
442932		BeanZ	K blocks (IZhO14_blocks)	C++14	0 / 100	1 ms	332 KiB

blocks

// I_Love_LPL 11m
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl '\n'
const int N = 1e5 + 5;
long long mod = 1000007;
const int lim = 4e5 + 5;
const int lg = 20;
const int base = 311;
const long double eps = 1e-6;
ll mx[N][lg + 1], dp[N][105], a[N];
ll get(ll l, ll r){
    ll l2 = __lg(r - l + 1);
    return max(mx[l][l2], mx[r - (1 << l2) + 1][l2]);
}
void DP(ll t, ll l, ll r, ll optl, ll optr){
    if (l > r) return;
    ll mid = (l + r) >> 1;
    dp[mid][t] = 1e18;
    ll opt;
    for (int i = optl; i <= min(optr, mid - 1); i++){
        ll cost = dp[i][t - 1] + get(i + 1, mid);
        if (dp[mid][t] > cost){
            dp[mid][t] = cost;
            opt = i;
        }
    }
    DP(t, l, mid - 1, optl, opt);
    DP(t, mid + 1, r, opt, optr);
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    if (fopen("tests.inp", "r")){
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }
    ll n, k;
    cin >> n >> k;
    for (int i = 1; i <= n; i++){
        cin >> a[i];
        mx[i][0] = a[i];
    }
    for (int i = 1; i <= lg; i++){
        for (int j = 1; (j + (1 << i) - 1) <= n; j++){
            mx[j][i] = max(mx[j][i - 1], mx[j + (1 << (i - 1))][i - 1]);
        }
    }
    for (int i = 1; i <= n; i++){
        dp[i][1] = max(dp[i - 1][1], a[i]);
    }
    for (int i = 2; i <= k; i++){
        DP(i, 1, n, 1, n);
    }
    cout << dp[n][k];
}
/*
Ans:

Out:
*/

Compilation message (stderr)

blocks.cpp: In function 'int main()':
blocks.cpp:36:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |         freopen("test.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
blocks.cpp:37:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |         freopen("test.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
blocks.cpp: In function 'void DP(long long int, long long int, long long int, long long int, long long int)':
blocks.cpp:29:7: warning: 'opt' may be used uninitialized in this function [-Wmaybe-uninitialized]
   29 |     DP(t, l, mid - 1, optl, opt);
      |     ~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 14
• Subtask 2: 0 / 18
• Subtask 3: 0 / 21
• Subtask 4: 0 / 47