Submission #1184141

#	Time	Username	Problem	Language	Result	Execution time	Memory
1184141		hoa208	Bigger segments (IZhO19_segments)	C++20	13 / 100	1 ms	328 KiB

segments

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i++)
#define FORD(i, b, a) for (int i = (b), _a = (a); i >= _a; i--)
#define pa pair<ll, ll>
#define fi first
#define se second
#define bit(mask, j) ((mask >> j) & 1)
#define t_test int t;cin >> t;while(t--)
const   ll mod = 1e9 + 7;
const   ll INF = 1e18;
inline  void adm(ll &x){if(x>=mod)x%=mod;else if(x<0)x+=mod;}
//--------------------------------------------------------------------
const ll N = 500003;
pa dp[N];
ll a[N], n, s[N];
ll get_sum(ll u, ll v) {
    return s[v] - s[u -1];
}
deque<ll> q;
void hbmt() {
    cin >> n;
    FOR(i, 1, n) {
        cin >> a[i];
        s[i] = s[i - 1] + a[i];
        dp[i] = {-INF, INF};
    }
    dp[0] = {0, 0};
    q.push_back(0);
    ll id = 1;
    FOR(i, 1, n) {
        ll sum = 0, j = 0;
        while(!q.empty() && dp[q.front()].se <= get_sum(q.front() + 1, i)) {
            j = q.front();
            dp[i] = {dp[j].fi + 1, get_sum(q.front() + 1, i)};
            q.pop_front();
        }
        q.push_front(j);
        while(!q.empty() && dp[q.back()].se > dp[i].se) {
            q.pop_back();
        }
        q.push_back(i);
        
        // cout << dp[i].fi << ' ' << dp[i].se << '\n';
    }
    cout << dp[n].fi << '\n';

}

int main() {
    
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    
    if(fopen("hbmt.inp", "r")) {
        freopen("hbmt.inp", "r", stdin);
        freopen("hbmt.ans", "w", stdout);
    }
    
    // t_test 
    hbmt();
    return 0;
}

Compilation message (stderr)

segments.cpp: In function 'int main()':
segments.cpp:57:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |         freopen("hbmt.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
segments.cpp:58:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   58 |         freopen("hbmt.ans", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 0 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27