Question

How to check if the last index of an array is reachable by jumping based on element values from index 0 in JavaScript

Answer 1

function canReachLastIndex(arr) {
    let size = arr.length;
    let currentIndex = 0;

    while (currentIndex < size) {
        // If we reach the last index, return true
        if (currentIndex === size - 1) {
            return true;
        }

        // If jump goes out of bounds, stop
        if (currentIndex + arr[currentIndex] >= size) {
            return false;
        }

        // Move to the next index by jumping
        currentIndex += arr[currentIndex];
    }

    return false;
}

function main() {
    const arr = [2, 3, 1, 1, 4];

    if (canReachLastIndex(arr)) {
        console.log("Yes, we can reach the last index.");
    } else {
        console.log("No, we cannot reach the last index.");
    }
}

main();



/*
run:

Yes, we can reach the last index.

*/

 

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