Merge-sort Algorithm

#include<iostream>
#include<algorithm>
#include<cmath>
using namespace std;
int bsearch(int data[],int n,int val)
{
	int low=0;
	int high=n-1;
	while(low<high)
	{
		int mid=(low+high)/2;
		if(data[mid]==val)
			return(mid);
		else if(data[mid]>val)
			high=mid-1;
		else if(data[mid]<val)
			low=mid+1;
	}
}
int main()
{
	int n;
	cin>>n;
	int arr[n],temp[n];

#include<bits/stdc++.h>
using namespace std;
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    long long n,k;
    cin>>n>>k;
    long long a[n],i,j;
    for(i=0;i<n;i++)
        cin>>a[i];
    sort(a,a+n);
    long long count=0;
    for(i=0,j=1;i<n;)
    {
        if(abs(a[i]-a[j])>=k)
        {
            count+=(n-j);
            i++;
        }
        else
            j++;
    }
    cout<<count;

My code runs well when i use int type but it shows compile time error on using long long type. Can anyone please sort out the bug int the code?

#include<iostream>
#include<vector>
#include<algorithm>
#define MAX 1000000
using namespace std;
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	long long a[MAX][MAX],m,i,j;
	cin>>m;
	for(i=0;i<m;i++)
	{
		for(j=0;j<2;j++)
		{
			cin>>a[i][j];
		}
	}
	for(i=0;i<m;i++)

I got it. Thank you!

Just follow this strategy : Pick a question. Think about it. Code it. Get it accepted. Learn the concept behind it. March on.

Happy Coding!

What does max_length_position=s mean? Also, can you please state the reason of using start=i+2?

Friends, this is my code for this problem. It is not behaving the way it should. Can anyone please hep me to find the error. Thanks in advance!

#include<iostream>
#include<vector>
using namespace std;
int main()
{
	vector<int> stack;
	long int n;
	long long 
	int h,x;
	cin>>n>>h;
	for(int i=0;i!=n;i++)
	{
		cin>>x;
		stack.push_back(x);
	}
	vector<int>::iterator iter=stack.begin(),iter_end=stack.end(),iter_beg=stack.begin();
	int cmd=1;
	while(cmd!=0)
	{