Submission #1119546

#	Time	Username	Problem	Language	Result	Execution time	Memory
1119546		luvna	K blocks (IZhO14_blocks)	C++14	0 / 100	1 ms	596 KiB

blocks

#include<bits/stdc++.h>

#define MASK(i) (1 << (i))
#define pub push_back
#define all(v) v.begin(), v.end()
#define compact(v) v.erase(unique(all(v)), end(v))
#define pii pair<int,int>
#define fi first
#define se second
#define endl "\n"
#define sz(v) (int)(v).size()
#define dbg(x) "[" #x " = " << (x) << "]"

using namespace std;

template<class T> bool minimize(T& a, T b){if(a > b) return a = b, true;return false;}
template<class T> bool maximize(T& a, T b){if(a < b) return a = b, true;return false;}

typedef long long ll;
typedef long double ld;

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rand(ll l, ll r){return uniform_int_distribution<ll>(l, r)(rng);}

const int N = 1e5 + 15;
const int MOD = 1e9 + 7;

int n, k;
int a[N];
int dp[2][N];
bool past = 0, succ = 1;

void dnc(int l, int r, int bestL, int bestR){
    if(l > r) return;

    int mid = (l+r) >> 1;

    int pos = -1;

    dp[succ][mid] = MOD;
    int mx = 0;

    for(int i = min(mid,bestR); i >= bestL; i--){
        maximize(mx, a[i]);
        if(minimize(dp[succ][mid], dp[past][i-1] + mx)) pos = i;
    }

    dnc(l,mid-1,bestL,pos);
    dnc(mid+1,r,pos,bestR);
}

void solve(){
    cin >> n >> k;

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

    dp[past][0] = 0; for(int i = 1; i <= n; i++) dp[past][i] = MOD;

    for(int i = 1; i <= k; i++){
        dnc(1,n,1,n);
        swap(past, succ);
        dp[past][0] = MOD;
    }

    cout << dp[past][n];
}

signed main(){
    ios_base::sync_with_stdio(NULL);
    cin.tie(0); cout.tie(0);

    #define task "task"

    if(fopen(task".INP", "r")){
        freopen(task".INP", "r", stdin);
        freopen(task".OUT", "w", stdout);
    }

    int t; t = 1; //cin >> t;
    while(t--) solve();
}

Compilation message (stderr)

blocks.cpp: In function 'int main()':
blocks.cpp:75:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |         freopen(task".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
blocks.cpp:76:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |         freopen(task".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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