注意点:
- 需要一开始build一次才能保证minn的正确性.
#include<cstdio>
#include<iostream>
using namespace std;
const int MAXN=2e6,INF=2e9,root=1;
struct Node{
int l,r;
int minn=INF,lazy;
}tr[4*MAXN];
int rest[MAXN];
void build(int now,int l,int r){
tr[now].l=l,tr[now].r=r;
if(l==r){
tr[now].minn=rest[l];
return;
}
int mid=(l+r)>>1;
build(now<<1,l,mid);
build((now<<1)|1,mid+1,r);
tr[now].minn=min(tr[now<<1].minn,tr[(now<<1)|1].minn);
}
void insert(int now,int ll,int rr,int val){
int l=tr[now].l,r=tr[now].r;
if(l>=ll&&r<=rr){
tr[now].minn+=val;
tr[now].lazy+=val;
return;
}
if(tr[now].lazy){
tr[now<<1].minn+=tr[now].lazy;
tr[now<<1].lazy+=tr[now].lazy;
tr[(now<<1)|1].minn+=tr[now].lazy;
tr[(now<<1)|1].lazy+=tr[now].lazy;
tr[now].lazy=0;
}
int mid=(l+r)>>1;
if(ll<=mid)insert(now<<1,ll,rr,val);
if(rr>mid)insert((now<<1)|1,ll,rr,val);
tr[now].minn=min(tr[now<<1].minn,tr[(now<<1)|1].minn);
}
int main(){
int n,m;
scanf("%d%d",&n,&m);
for(int i=1;i<=n;i++){
scanf("%d",&rest[i]);
}
build(root,1,n);
for(int i=1;i<=m;i++){
int d,s,t;
scanf("%d%d%d",&d,&s,&t);
insert(root,s,t,-d);
if(tr[root].minn<0){
printf("-1\n");
printf("%d\n",i);
return 0;
}
}
printf("0\n");
return 0;
}