Tosin Coker mini-challenge-4

src/count-islands/index.js

@@ -1,3 +1,37 @@
-function countIslands(grid) {}
+function countIslands(grid) {
+  let noOfRows = grid.length, noOfCols = grid[0].length; // matrix dimentions
+
+  let noOfIslands = 0;
+  let visited = []; // grid of visited islands on the latest iterations
+  let left = 0, // island on the left
+    up = 0; // island on the right
+
+  for (let row = 0; row < noOfRows; row++) {
+    for (let col = 0; col < noOfCols; col++) {
+      if (!grid[row][col]) {
+        continue; // skip zero (water)
+      }
+      left = col > 0 ?
+        grid[row][col - 1] :
+        0;
+
+      up = row > 0 ?
+        grid[row - 1][col] :
+        0;
+      if (!left && !up) { // new island starts if there is water on the left and up
+        noOfIslands++;
+        grid[row][col] = noOfIslands; // give a number to island
+      } else if (left && up && left !== up) { //upper island is not seperate
+        grid[row][col] = left;
+        visited.push(up)
+      } else if (left) {
+        grid[row][col] = left; // island continues previous island to the right
+      } else if (up) {
+        grid[row][col] = up; // island continues previous island
+      }
+    }
+  }
+  return noOfIslands - visited.length;
+}
 
 module.exports = countIslands;

src/word-search/index.js

@@ -1,3 +1,31 @@
-function wordSearch(words, word) {}
+function wordSeartemp(words, word) {
+  if (word === "") return true;
 
-module.exports = wordSearch;
+  for (var row = 0; row < words.length; row++) {
+    for (var col = 0; col < words[row].length; col++) {
+      if (words[row][col] === word[0]) {
+        if (transversal(0, row, col)) return true;
+      }
+    }
+  }
+  return false;
+  function transversal(wordPosition, x, y) {
+    if (wordPosition === word.length) return true;
+    if (!words[x] || !words[x][y]) return false;
+    if (words[x][y] !== '%%' && words[x][y] === word[wordPosition]) {
+      let tempStorage = words[x][y];
+      words[x][y] = '%%';
+
+      if (transversal(wordPosition + 1, x - 1, y)) return true; //up
+      if (transversal(wordPosition + 1, x + 1, y)) return true; //down
+      if (transversal(wordPosition + 1, x, y - 1)) return true; //left
+      if (transversal(wordPosition + 1, x, y + 1)) return true; //right
+      words[x][y] = tempStorage; // backtracking
+    }
+    return false;
+  }
+};
+
+
+
+module.exports = wordSeartemp;