Problem:
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The Maximum Number of Customers

$N$ persons visited a restaurant. The restaurant is open from 0 to $T$. The $i$-th person entered the restaurant at $l_i$ and left at $r_i$. Find the maximum number of persons during the business hours.

Constraints

$ 1 \leq N \leq 10^5 $

$ 1 \leq T \leq 10^5 $

$ 0 \leq l_i < r_i \leq T $

Input

The input is given in the following format.

$N$ $T$

$l_1$ $r_1$

$l_2$ $r_2$

:

$l_N$ $r_N$

Output

Print the maximum number of persons in a line.

Sample Input 1

6 10
0 2
1 3
2 6
3 8
4 10
5 10

Sample Output 1

4

Sample Input 2

2 2
0 1
1 2

Sample Output 2

1

Solution in C++ (judge verdict: Accepted)

#include <bits/stdc++.h>
using namespace std;

int main() {
  int n,m;
  cin>>n>>m;
  int d[m+2];
  memset(d,0,sizeof(d));
  for(int i=0,x,y;i<n;i++){
    cin>>x>>y;
    d[x+1]++;
    d[y+1]--;
  }
  int ans=0;
  for(int i=1;i<=m;i++){
    d[i]+=d[i-1];
    ans=max(ans,d[i]);
  }
  cout<<ans<<endl;
  return 0;
}