fix: handle the case when target is last in jumpSearch (#231)

Author: vil02

search/jump_search.ts

@@ -25,13 +25,13 @@ export const jumpSearch = (array: number[], target: number): number => {
     let currentIdx: number = 0,
         stepSize: number = Math.floor(Math.sqrt(array.length)),
         nextIdx: number = stepSize;
-        
+
     while (array[nextIdx - 1] < target) {
         currentIdx = nextIdx;
         nextIdx += stepSize;
 
-        if (nextIdx >= array.length) {
-            nextIdx = array.length - 1;
+        if (nextIdx > array.length) {
+            nextIdx = array.length;
             break;
         }
     }

search/test/jump_search.test.ts

@@ -5,6 +5,15 @@ describe("Jump search", () => {
     [[], 1, -1],
     [[1, 2, 3, 4, 5], 4, 3],
     [[1, 3, 5, 8, 9], 4, -1],
+    [[1, 3, 5, 8], 8, 3],
+    [[1, 3, 5, 8], 9, -1],
+    [[1, 3, 5, 8], 7, -1],
+    [[1, 3, 5, 8, 10], 10, 4],
+    [[1, 3, 5, 8, 10], 11, -1],
+    [[1, 3, 5, 8, 10], 9, -1],
+    [[5], 5, 0],
+    [[5], 100, -1],
+    [[], 100, -1],
   ])(
     "of %o , searching for %o, expected %i",
     (array: any[], target: any, index: number) => {