Submission #1279057

#	Time	Username	Problem	Language	Result	Execution time	Memory
1279057		rexdino	K blocks (IZhO14_blocks)	C++20	100 / 100	169 ms	84000 KiB

blocks

#include <bits/stdc++.h>
#define fi first
#define se second
#define FOR(i,a,b) for(int i=(a); i<=(b); ++i)
#define REP(i,a,b) for(int i=(a); i>=(b); --i)
#define BIT(x, i) (((x) >> (i)) & 1)
#define MASK(i) (1LL << (i))
#define sz(v) (int)(v).size()
#define ALL(v) (v).begin(),(v).end()
#define printArr(a, n) for (int i=1; i<=n; ++i) cout << a[i] << " "; el;
#define el cout << "\n"
using namespace std;

typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

const int N = 1e6 + 5;
const int mod = 1e9 + 7;
const int base = 311;
const ll INF = 1e18;

/// REXDINO FROM LTV HSGS ///
int n, k, a[N];
stack<pii> st;
ll dp[100005][105];

void solve(){
    cin >> n >> k;
    FOR(i, 1, n) cin >> a[i];

    memset(dp, 0x3f, sizeof dp);
    dp[0][0] = 0;
    FOR(j, 1, k) {
        stack<pll> st;
        FOR(i, 1, n){
            ll mn = dp[i - 1][j - 1];
            while(!st.empty() && a[st.top().fi] <= a[i]){
                mn = min(mn, st.top().se);
                st.pop();
            }

            dp[i][j] = mn + a[i];
            if (!st.empty()) dp[i][j] = min(dp[i][j], dp[st.top().fi][j]);
            st.push({i, mn});
        }
    }

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

signed main(){
    #define NAME "blocks"
    if (fopen(NAME".inp", "r")){
        freopen(NAME".inp", "r", stdin);
        freopen(NAME".out", "w", stdout);
    }
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

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

    return 0;
}

Compilation message (stderr)

blocks.cpp: In function 'int main()':
blocks.cpp:55:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   55 |         freopen(NAME".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
blocks.cpp:56:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |         freopen(NAME".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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