Big O Notation Examples

RoughWork.js

// Calculate the sum of all numbers from 1 - 10
// O(n)
function addUpToOne(n) {
 return n * (n +1) / 2;
}

var timeOne = performance.now();
addUpToOne(10000000);
var timeTwo = performance.now();
console.log(`Time taken 2: ${(timeTwo - timeOne) / 1000} seconds`)

// O(1)
function addUpToTwo(n) {
 return n * (n +1) / 2;
}

var timeOne = performance.now();
addUpToTwo(10000000);
var timeTwo = performance.now();
console.log(`Time taken 2: ${(timeTwo - timeOne) / 1000} seconds`)



// O(n)
function countUpAndDown(input) {
    for (i=0; i<= input; i++) {
        console.log(i)
    }
}

countUpAndDown(10);



// O(n^2)
function printAllPairs(input) {
    
    for ( i = 0; i < input; i++) {
        for (j = 0; j < input; j++) {
            console.log(i, j)
        }
    }
}

printAllPairs(10);



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