Breaking News: Grepper is joining You.com. Read the official announcement!

cpp count occrances efficient solution

ROCKETMAN answered on July 29, 2022 Popularity 1/10 Helpfulness 1/10

answer cpp count occrances efficient solution

cpp count occrances efficient solution

Comment

//COUNT OCCURANCES IN A SORTED ARRAY EFFICIENT SOLUTION.
#include<bits/stdc++.h>
using namespace std;
int LAST_OCCURANCE(int a[],int n, int x)
{
	int l=0,h=n-1;
	while(l<=h)
	{
		int mid=(l+h)/2;
		if(a[mid]>x) h=mid-1;
		else if(a[mid]<x) l=mid+1;
		else 
		{
			if(mid==n || a[mid+1]!=a[mid]) return mid;
			else l=mid+1;
		}
	}
}
int FIRST_OCCURANCE(int a[],int n,int x)
{
	int l=0,h=n-1;
	int ans;
	while(l<=h)
	{
		int mid=(l+h)/2;
		if(a[mid]>x) h=mid-1;
		else if(a[mid]<x) l=mid+1;
		else
		{
			if(mid==0 || a[mid-1]!=a[mid]) return mid;
			else h=mid-1;	
		}
	}
	return -1;
}
int COUNT_OCCURANCES(int a[],int n,int x)
{
	int first=FIRST_OCCURANCE(a,n,x);
	if(first==-1) return 0; // element not present
	else return(LAST_OCCURANCE(a,n,x)-first+1);
}
int main()
{
	int n;
	cin>>n;
	int a[n];
	for(int i=0;i<n;i++) cin>>a[i];
	int x;
	cin>>x;
	cout<<COUNT_OCCURANCES(a,n,x)<<endl;
	return 0;
}

Popularity 1/10 Helpfulness 1/10 Language cpp

Source: Grepper

Tags: c++ count solution

Link to this answer
Share Copy Link

Contributed on Jul 29 2022

ROCKETMAN

0 Answers Avg Quality 2/10

Continue with Google

By continuing, I agree that I have read and agree to Greppers's Terms of Service and Privacy Policy.

cpp count occrances efficient solution

Contents

More Related Answers

cpp count occrances efficient solution

Grepper

Documentation

Social

Legal

Contact

Oops, You will need to install Grepper and log-in to perform this action.