Finding the length of connected cells of 1's (regions) in an matrix of 1's and 0's
import java.io.*; class GFG { static int max = 0; static int count = 0; public static void traverse(int a[][], int r, int c, int i, int j) { if (i >= r || j >= c || i < 0 || j < 0) { return; } if (a[i][j] == 0) { return; } else { a[i][j] = 0; count++; traverse(a, r, c, i - 1, j); traverse(a, r, c, i, j - 1); traverse(a, r, c, i + 1, j); traverse(a, r, c, i, j + 1); traverse(a, r, c, i - 1, j - 1); traverse(a, r, c, i + 1, j + 1); traverse(a, r, c, i - 1, j + 1); traverse(a, r, c, i + 1, j - 1); } } public static void main(String[] args) { int R = 5; int C = 5; int a[][] = { { 0, 0, 0, 0, 0}, { 0, 1, 1, 0, 0}, { 0, 0, 1, 0, 1}, { 1, 0, 0, 0, 1}, { 0, 1, 0, 1, 1} }; for (int i = 0; i < R; i++) { for (int j = 0; j < C; j++) { if (a[i][j] == 1) { count = 0; traverse(a, R, C, i, j); if (count > max) { max = count;