Submission #92530

#	Time	Username	Problem	Language	Result	Execution time	Memory
92530		3zp	Divide and conquer (IZhO14_divide)	C++14	100 / 100	140 ms	14760 KiB

divide

#include<bits/stdc++.h>
using namespace std;
const int maxn = 300009;
int n;
long long e[maxn], E[maxn];
long long g[maxn], G[maxn];
long long x[maxn], X[maxn];
long long a[maxn], b[maxn], f[maxn];
void upd(long long x, long long d){
    while(x <= 2*n+1){
        f[x] = min(f[x], d);
        x += (x & -x);
    }
}
long long cnt(long long x){
    long long ans = 1e18;
    while(x){
        ans = min(ans, f[x]);
        x -= (x & -x);
    }
    return ans;
}
main(){
    cin >> n;
    for(long long i = 1; i <= n; i++){
        cin >> x[i] >> g[i] >> e[i];
        X[i] = x[i] ;
        G[i] = g[i] + G[i - 1];
        E[i] = e[i] + E[i - 1];
    }
    //E[r] - E[l] > X[r] - X[l + 1] ---> G[r] - G[l]

    vector<pair<long long,long long> > v;
    for(long long i = 0; i <= n; i++){
        v.push_back({E[i] - X[i], i + n + 1});
        v.push_back({E[i] - X[i + 1], i});
    }
    sort(v.begin(), v.end());
    for(long long i = 0; i < v.size(); i++)
        if(v[i].second <= n) b[v[i].second] = i + 1;
        else a[v[i].second - n - 1] = i + 1;
    for(long long i = 1; i <= 3*n+1; i++)
        f[i] = 1e18;
    long long ans = 0;
    for(long long i = 0; i <= n; i++){
        
        long long T = cnt(a[i] - 1);
        ans = max(ans, G[i] - T);
        upd(b[i], G[i]);
    }
    cout << ans << endl;
}

Compilation message (stderr)

divide.cpp:23:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){
      ^
divide.cpp: In function 'int main()':
divide.cpp:39:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(long long i = 0; i < v.size(); i++)
                          ~~^~~~~~~~~~

• Subtask 1: 17 / 17
• Subtask 2: 31 / 31
• Subtask 3: 52 / 52