find-smallest-common-number

find-the-smallest-common-number.js

const findSmallestCommonNumber = function(inputArr1, inputArr2, inputArr3){
	let index1  = 0;
	let index2  = 0;
	let index3  = 0;
	let currentMax = Number.MIN_VALUE;
	// if we go overflow on any array we can stop the loop
	while(index1 <inputArr1.length && index2 < inputArr2.length && index3<inputArr3.length){
		if(inputArr1[index1] === inputArr2[index2] && inputArr2[index2] == inputArr3[index3]){
			return inputArr1[index1];
		}
		currentMax = Math.max(inputArr1[index1],inputArr2[index2],inputArr3[index3]);
		if(inputArr1[index1] < currentMax){
			index1++;
		}
		if(inputArr2[index2] < currentMax){
			index2++;
		}
		if(inputArr3[index3] < currentMax){
			index3++;
		}
	}

	// safely return -1 if we finish any of the arrays without a match.
	return -1;
}

let inputArr1 = [1, 4, 6, 7, 8, 10, 14];
let inputArr2 = [1, 4, 5, 6, 7, 8, 50];
let inputArr3 = [0, 6, 7, 8, 10, 25, 30, 40];

let res = findSmallestCommonNumber(inputArr1,inputArr2, inputArr3);

console.log(res);

inputArr1 = [1, 4, 6, 7, 8, 10, 14];
inputArr2 = [1, 4, 5, 7, 8, 50];
inputArr3 = [];

res = findSmallestCommonNumber(inputArr1,inputArr2, inputArr3);

console.log(res);