cpp-lab/firstAndLastOccurance.cpp at main · Dev-Arijit/cpp-lab · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
#include <iostream>
using namespace std;

int firstOcc(int arr[],int size,int key){
    int s = 0;
    int e = size - 1;
    int ans=-1,mid = s + (e-s)/2;
    while(s <= e){
        if(arr[mid] == key){
            ans = mid;
            e = mid-1;
        }
        else if(arr[mid] < key){
            s = mid + 1;

        }
        else{
            e = mid-1;
        }
        mid = s + (e-s)/2;
    }
    return ans;
}

int lastOcc(int arr[],int size,int key){
    int s = 0;
    int e = size - 1;
    int ans=-1,mid = s + (e-s)/2;
    while(s <= e){
        if(arr[mid] == key){
            ans = mid;
            s = mid+1;
        }
        else if(arr[mid] < key){
            s = mid + 1;

        }
        else{
            e = mid-1;
        }
        mid = s + (e-s)/2;
    }
    return ans;
}


int main(){
    int even[6] = {1,2,3,3,3,5};
    cout << firstOcc(even,6,3) << endl;
    cout << lastOcc(even,6,3) << endl;

}