islands

Author: specialtactics

week3/number-of-islands.c

@@ -0,0 +1,72 @@
+void iterateSquare(int **seen, char** grid, int vertical, int startingHorizontal, int maxI, int maxJ);
+
+int numIslands(char** grid, int rows, int* cols){
+ int **seen = (int **)malloc(rows * sizeof(int*));
+ for (int i = 0; i < rows; ++i) {
+ seen[i] = (int *)malloc((*cols) * sizeof(int));
+ for (int j = 0; j < *cols; ++j) {
+ seen[i][j] = 0;
+ }
+ }
+ int islands = 0;
+
+ // Loop through
+ for (int i = 0; i < rows; ++ i) {
+ for (int j = 0; j < *cols; ++j) {
+ if (seen[i][j] == 0 && grid[i][j] == '1') {
+ ++islands;
+ iterateSquare(seen, grid, i, j, rows, *cols);
+ }
+ }
+ }
+ 
+ for (int i = 0; i < rows; ++i) free(seen[i]);
+ free(seen);
+ 
+ return islands;
+}
+
+
+void iterateSquare(int **seen, char** grid, int vertical, int startingHorizontal, int maxI, int maxJ) {
+ // Horizonally right
+ for (int b = startingHorizontal; b < maxJ; ++b) {
+ if (grid[vertical][b] != '1') {
+ break;
+ } else {
+ seen[vertical][b] = 1;
+
+ if (vertical - 1 >= 0) {
+ if (grid[vertical-1][b] == '1' && seen[vertical-1][b] == 0) {
+ iterateSquare(seen, grid, vertical - 1, b, maxI, maxJ); 
+ } 
+ }
+ if (vertical + 1 < maxI) {
+ printf("1| %d, %d\n", vertical+1, b);
+ if (grid[vertical+1][b] == '1' && seen[vertical+1][b] == 0) {
+ iterateSquare(seen, grid, vertical + 1, b, maxI, maxJ); 
+ } 
+ }
+ }
+ }
+
+ // Horizonally left
+ for (int b = (startingHorizontal - 1); b >= 0; --b) {
+ if (grid[vertical][b] != '1') {
+ break;
+ } else {
+ seen[vertical][b] = 1;
+
+ if (vertical - 1 >= 0) {
+ if (grid[vertical-1][b] == '1' && seen[vertical-1][b] == 0) {
+ iterateSquare(seen, grid, vertical - 1, b, maxI, maxJ); 
+ } 
+ }
+ if (vertical + 1 < maxI) {
+ printf("2| %d, %d\n", vertical+1, b);
+ if (grid[vertical+1][b] == '1' && seen[vertical+1][b] == 0) {
+ iterateSquare(seen, grid, vertical + 1, b, maxI, maxJ); 
+ } 
+ }
+ }
+ }
+}