Submission #433247

#	Time	Username	Problem	Language	Result	Execution time	Memory
433247		cpp219	Bigger segments (IZhO19_segments)	C++14	100 / 100	100 ms	20804 KiB

segments

#pragma GCC optimization "O2"
#pragma GCC optimization "unroll-loop"
#pragma GCC target ("avx2")

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define fs first
#define sc second
using namespace std;
const ll N = 5e5 + 9;
const ll mod = 1e9 + 7;
const ll base = 31;
typedef pair<ll,ll> LL;

ll n,a[N],pre[N],dp[N],best[N];

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    #define task "tst"
    if (fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        //freopen(task".out", "w", stdout);
    }
    cin>>n;
    for (ll i = 1;i <= n;i++) cin>>a[i],pre[i] = pre[i - 1] + a[i];
    for (ll i = 1;i <= n;i++){
        best[i] = max(best[i],best[i - 1]);
        dp[i] = dp[best[i]] + 1;
        ll cur = 2*pre[i] - pre[best[i]];
        ll nxt = lower_bound(pre + 1,pre + n + 1,cur) - pre;
        best[nxt] = max(best[nxt],i);
    }
    cout<<dp[n];
}

Compilation message (stderr)

segments.cpp:1: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    1 | #pragma GCC optimization "O2"
      | 
segments.cpp:2: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    2 | #pragma GCC optimization "unroll-loop"
      | 
segments.cpp: In function 'int main()':
segments.cpp:23:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   23 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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