Question

How to find the starting and ending position of a given value in a sorted integer array in C

Answer 1

#include <stdio.h>

void findStartingEndingPosition(int arr[], int size, int value, int result[]) {
    result[0] = -1;
    result[1] = -1;
    
    int i;
    
    for (; i < size - 1; i++) {
        if (arr[i] == value) {
            result[0] = i;
            result[1] = i;
            break;
        }
    }
    
    for (int j = i; j < size - 1; j++) {
        if (arr[j] == arr[j + 1]) {
            result[1] = j + 1;
        } else {
            break;
        }
    }
}

int main() {
    int arr[] = {1, 3, 4, 7, 7, 8, 8, 10, 11};
    int size = sizeof(arr) / sizeof(arr[0]);
    int value = 8;
    int result[2];
    
    findStartingEndingPosition(arr, size, value, result);
    
    printf("start: %d\n", result[0]);
    printf("end: %d\n", result[1]);
    
    return 0;
}



/*
run:

start: 5
end: 6

*/

 

70+ SQL courses for beginners and professionals