Submission #1192274

#	Time	Username	Problem	Language	Result	Execution time	Memory
1192274		quocbaoo	Divide and conquer (IZhO14_divide)	C++20	100 / 100	34 ms	6352 KiB

divide

#include<bits/stdc++.h>
#define ll long long
#define fi first
#define se second
using namespace std;
ll pr[100004],st[400005],pr1[100004],a[100004],g[100004],d[100004];
void update(int id,int l,int r,int u,ll v){
    if (l>u||r<u) return ;
    if (l==r) {
        st[id]=v;return ;
    }
    int mid=(l+r)/2;
    update(id*2,l,mid,u,v);update(id*2+1,mid+1,r,u,v);
    st[id]=min(st[id*2],st[id*2+1]);
}
int get(int id,int l,int r,int u,int v,ll z){
    if (l>v||r<u) return -1;
    if (st[id]>z) return -1;
    if (l==r) return l;
    int mid=(l+r)/2;
    int ans=-1;
    if (st[id*2]<=z) ans=get(id*2,l,mid,u,v,z);
    if (ans==-1) ans=get(id*2+1,mid+1,r,u,v,z);
    return ans;
}
int main() {
    if (fopen("divide.in","r")){
        freopen("divide.in","r",stdin);
        freopen("divide.out","w",stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int n;cin>>n;ll ans=0;
    for (int i=1;i<=n;i++){
        cin>>a[i]>>g[i]>>d[i];
    }
    for (int i=1;i<=n;i++){
        pr[i]=pr[i-1]+d[i];
        pr1[i]=pr1[i-1]+g[i];
        if (pr[i]-a[i]>=-a[1]){
            ans=max(ans,pr1[i]);
        }
        else{
            int z=get(1,1,n,1,i-1,pr[i]-a[i]);
            if (z!=-1) ans=max(ans,pr1[i]-pr1[z]);
        }
        update(1,1,n,i,pr[i]-a[i+1]);
    }
    cout<<ans;
}

Compilation message (stderr)

divide.cpp: In function 'int main()':
divide.cpp:28:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |         freopen("divide.in","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
divide.cpp:29:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |         freopen("divide.out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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