Blue Bridge Cup points to Apple Prefix and Difference

Problem Description

　　The children lined up and the teacher gave them apples.
　　Children mark 1..N from left to right. There are M teachers. Each time the i-th teacher will give Li to Ri, a total of Ri-Li + 1 children will send Ci apples each.
　　Finally, the teacher wants to know how many apples each child has.

Input format

　　The two integers N and M in the first line indicate the number of children and the number of teachers.
　　In the next M lines, there are three integers Li, Ri, and Ci in each line. The meaning is as stated in the title.

Output format

　　A row of N numbers, the ith number represents the fruit in the ith child's hand.

Sample input

5 3
1 2 1
2 3 2
2 5 3

Sample output

1 6 5 3 3

Data size and agreement

　　For 40% of the data, N and M ≤ 1 000.
　　For 100% of the data, N, M≤100 000, 1≤Li≤Ri≤N, 0≤Ci≤100.

Prefix and difference knowledge points are forgotten, to be reviewed.

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 int a[100010];
 4 int main() {
 5     int n, m;
 6     cin >> n >> m;
 7     while (m--) {
 8         int l, r, c;
 9         cin >> l >> r >> c;
10         a[r] += c;
11         a[l - 1] -= c;
12     }
13     for (int i = n - 1; i >= 1; i--) {
14         a[i] += a[i + 1];
15     }
16     for (int i = 1; i <= n; i++) {
17         cout << a[i] << " ";
18     }
19     return 0;
20 }