线段树维护的信息就是区间最小值，进行教室的订单的时候，将相应的区间减去值就可以了，然后查询区间是否出现小于0的数，出现了则不满足，即是答案。

#include <bits/stdc++.h>
#define go continue
#define IOS ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define fory(i,a,b) for(int i = a; i <= b; ++i)
using namespace std;template <typename T> inline void read(T& t)
{int f = 0, c = getchar();t = 0;while (!isdigit(c)) f |= c == '-', c = getchar();while (isdigit(c)) t = t * 10 + c - 48, c = getchar();if (f) t = -t;
}template <typename T> void print(T x)
{if (x < 0) x = -x, putchar('-');if (x > 9) print(x / 10);putchar(x % 10 + 48);
}
//--------------------------------------------
const int N = 1000010;int n, m;
int a[N];
int x, y, z;struct node
{int l, r, minn, lazy;
};struct segment_tree
{node t[N << 2];inline void push_down(int root){if(t[root].lazy != 0){//cal_lazy 计算lazy对当前线段的影响t[root].minn += t[root].lazy;if(t[root].l != t[root].r){int ch = root << 1;//union_lazy 将lazy传递到两个子节点t[ch].lazy += t[root].lazy;t[ch + 1].lazy += t[root].lazy;}//init_lazy 清空当前lazyt[root].lazy = 0;}}inline void push_up(int root){int ch = root << 1;push_down(ch);push_down(ch + 1);t[root].minn = min(t[ch].minn, t[ch + 1].minn);}inline void build(int root, int l, int r){t[root].l = l;t[root].r = r;//init_lazyt[root].lazy = 0;if(l != r){int ch = root << 1;int mid = (l + r) >> 1;build(ch, l, mid);build(ch + 1, mid + 1, r);push_up(root);}else t[root].minn = a[l];}inline void change(int root, int l, int r, int add){push_down(root);if(t[root].l == l && t[root].r == r){t[root].lazy += add;return;}int ch = root << 1;int mid = (t[root].l + t[root].r) >> 1;if(r <= mid) change(ch, l, r, add);else if(l > mid) change(ch + 1, l, r, add);else{change(ch, l, mid, add);change(ch + 1, mid + 1, r, add);}push_up(root);}inline int query(int root, int l, int r){push_down(root);if(t[root].l == l && t[root].r == r){return t[root].minn;}int ch = root << 1;int mid = (t[root].l + t[root].r) >> 1;if(r <= mid) return query(ch, l, r);else if(l > mid) return query(ch + 1, l, r);else return min(query(ch, l, mid), query(ch + 1, mid + 1, r));}
} st;signed  main()
{read(n), read(m);fory(i, 1, n) read(a[i]);st.build(1, 1, n);fory(i, 1, m){read(z), read(x), read(y);st.change(1, x, y, -z);int ok = st.query(1, x, y);if(ok < 0){puts("-1");print(i);return 0;}}puts("0");return 0;}