sicily--1145. 校门外的树

一开始没看到起点是0就 WA 了2次，其余没什么了

#include<iostream>#include<cstring>using namespace std;int main(){int tree[10001];//奢侈点，哈哈memset(tree, 0, sizeof(tree));//1表示种有树int length, num;cin >> length >> num;for(int i = 0; i <= length;i++){tree[i] = 1;}for(int j = 0; j < num; j++){int start, end;cin >> start >> end;for(int k = start; k <= end; k++){tree[k] = 0;}}int sum = 0;//表示最终剩余的树for(int j = 0; j <= length; j++)sum = sum + tree[j];cout << sum << endl;return 0;}