@[RLFXRMSC](/user/1029412)
问题不少
by xuzihao123 @ 2023-08-08 22:22:29
~~题解是个好东西~~
比如`for (int j = a; j < b; a++)`循环中应当更新j而非a；还有数组`tree`的初始化即每个元素为0，再设为0相当于没有操作。这里可以把0改成1。
by CoderMeow @ 2023-08-08 22:31:19
```
#include <iostream>
#include <cstring>
using namespace std;
int main()
{
int l;
cin>>l;
int trees[100003];
for(int i=0;i<=l;i++)trees[i]=1;
int m;
cin>>m;
int a,b;
for (int i = 0; i < m; i++)
{
cin >> a >> b;
for (int j=a;j<=b;j++)
{
trees[j]=0;
}
}
int num = 0;
for (int i = 0; i <=l; i++)
{
if(trees[i]==1)num++;
}
cout << num;
}
```
by xuzihao123 @ 2023-08-08 22:33:32