Cats Who Code

//2n awesome int [] productArray(int [] a){ int product = 1; for(int i=0; i

//spell same forward and backward //babad //aba or bab //worst and improve //generate all of substring whether each of them is palindrome and longest - n^3 //helper - expand from middle //base case when s is null or left index is greater than right index //while s.charAt(left) == s.charAt(right) then keep it going //not return right index - left index +1; //a abba c // 4-1+1 = 4 we're finding th..

//furstDuplicate //1) n^2 double for loop solution it's bad! we can do much better //update minimum index everytime finds smaller //access of array of index int firstDuplicate(int [] a){ int min_index = a.length; for(int i=0; i

the maximum sum of contiguous subarray method returning sum max_sum = Integer.MIN_VALUE; Brute Force algorithm iterate every possibility available double nested for loop - worst update max_sum for(int i=0; i

all lower case letters //double for loop //n^2 //once see duplicate then modify boolean var char firstNonRepeatingCharacter(String inputString){ for(int i=0; i

//good but we want to improve this boolean sumOfTwo(int [] a, int [] b, int v){ //iterate each if v - a[i] = b[i] then true otherwise false. for(int i=0; i

perfect square comes to row and column rotate the image by 90 degrees clockwise 1 2 3 7 4 1 4 5 6 -> 8 5 2 7 8 9 9 6 3 0,0 0,1 0,2 -> 0,2, 1,2 2,2 1,0 1,1 1,2 -> 0,1 1,1 2,1 2,0 2,1 2,2 -> 0,0 1,0 2,0 transpose just swap row and column -> then change the order of column 123 147 456 -> 258 -> 789 369 swap a[i,j] = a[j, i]; int [] [] rotateImage(int [] [] matrix){ int N = maxtrix.length; //swap co..