Example: Brute-Force Equilibrium Index

// Brute-Force Equilibrium Index
#include <stdio.h>

int findEquilibriumIndexBruteForce(int arr[], int n) {
    if (n == 0) return -1; // Handle empty array

    for (int i = 0; i < n; i++) {
        long long leftSum = 0;
        long long rightSum = 0;

        // Calculate left sum
        for (int j = 0; j < i; j++) {
            leftSum += arr[j];
        }

        // Calculate right sum
        for (int j = i + 1; j < n; j++) {
            rightSum += arr[j];
        }

        if (leftSum == rightSum) {
            return i; // Found an equilibrium index
        }
    }
    return -1; // No equilibrium index found
}

int main() {
    // Step 1: Define an array
    int arr[] = {-7, 1, 5, 2, -4, 3, 0};
    int n = sizeof(arr) / sizeof(arr[0]);

    // Step 2: Find the equilibrium index using brute force
    int equilibriumIndex = findEquilibriumIndexBruteForce(arr, n);

    // Step 3: Print the result
    if (equilibriumIndex != -1) {
        printf("Equilibrium index found at position: %d\n", equilibriumIndex);
    } else {
        printf("No equilibrium index found.\n");
    }

    // Test with another array
    int arr2[] = {1, 2, 3};
    int n2 = sizeof(arr2) / sizeof(arr2[0]);
    equilibriumIndex = findEquilibriumIndexBruteForce(arr2, n2);
    if (equilibriumIndex != -1) {
        printf("Equilibrium index for {1, 2, 3} found at position: %d\n", equilibriumIndex);
    } else {
        printf("No equilibrium index for {1, 2, 3} found.\n");
    }

    return 0;
}