题目大意:
N个方块 标号1~N
N个方块 标号1~N
K个操作 操作a b 表示标号a~b区间每位多加一个方块
Input
* Line 1: Two space-separated integers, N K.
* Lines 2..1+K: Each line contains one of FJ's instructions in the form of two space-separated integers A B (1 ≤ A ≤ B≤ N).
Output
* Line 1: The median height of a stack after Bessie completes the instructions.
Sample Input
7 4
5 5
2 4
4 6
3 5
Sample Output
1
即 有N = 7个方块,发出K = 4个指令。第一条指令是添加方块在堆栈5,第二个是添加方块到堆栈2..4等
输出细节:
操作完成后,堆栈的高度为 0, 1, 2, 3, 3, 1, 0。
中间堆栈高度为1,因为1是排序的顺序中的0, 0, 1, 1, 2, 3, 3。
区间表示法
#include <stdio.h>
#include <string.h>
#include <algorithm>
int flag[]={};
using namespace std;
int main()
{
int n,k;
scanf("%d%d",&n,&k);
while(k--)
{
int a,b;
scanf("%d%d",&a,&b);
flag[a]++;
flag[b+]--;
}
int sum=;
for(int i=;i<=n;i++)
{
sum+=flag[i];
flag[i]=sum;
}
sort(flag,flag+n+);
printf("%d\n",flag[n/+]); return ;
}