add code for chapters 1 and 2 in ts (#102)

02_selection_sort/ts/01_selection_sort.ts

@@ -0,0 +1,27 @@
+function findSmallestIndex<T>(array: T[]): number {
+  let smallestIndex: number = 0;
+  let smallestElement: T = array[smallestIndex];
+
+  for (let i: number = 1; i < array.length; i++) {
+    if (array[i] < smallestElement) {
+      smallestElement = array[i];
+      smallestIndex = i;
+    }
+  }
+
+  return smallestIndex;
+}
+
+function selectionSort<T>(array: T[]): T[] {
+  const sortedArray: T[] = [];
+  const length = array.length;
+
+  for (let i: number = 0; i < length; i++) {
+    const smallestIndex: number = findSmallestIndex(array);
+    sortedArray.push(array.splice(smallestIndex, 1)[0]);
+  }
+
+  return sortedArray;
+}
+
+console.log(selectionSort([5, 3, 6, 2, 10])); // [2, 3, 5, 6, 10]