P1083 借教室

#include<bits/stdc++.h>
using namespace std;
int num[1010000],dd[1010000],op[1010000],ed[1010000],n,m,cf[1010000];
inline int read()
{
    int ans=0;
    char ch=getchar();
    while(ch<‘0‘||ch>‘9‘)ch=getchar(); 
    while(ch>=‘0‘&&ch<=‘9‘)
    {ans=ans*10+ch-‘0‘;ch=getchar();}
    return ans;
}
inline int check(int t)
{
    memset(cf,0,sizeof(cf));
    for(int i=1;i<=t;i++)
    {cf[op[i]]-=dd[i];cf[ed[i]+1]+=dd[i];}
    for(int i=1;i<=n;i++)
    {cf[i]+=cf[i-1];if(cf[i]+num[i]<0)return 0;}
    return 1;
}
int main()
{
    cin>>n>>m;
    for(int i=1;i<=n;i++)num[i]=read();
    for(int i=1;i<=m;i++){dd[i]=read();op[i]=read();ed[i]=read();}
    if(check(m)){cout<<0;return 0;}
    int l=1,r=m-1,ans=0;
    while(l<=r)
    {
        int mid=(l+r)>>1;
        if(check(mid))ans=mid,l=mid+1;
        else r=mid-1;
    }
    cout<<-1<<endl<<ans+1;
}