Merge pull request deutranium#209 from rcchcz/PR

Jump search in C++

Author: deutranium

searchingAlgo/jumpSearch/jumpSearch.cpp

@@ -0,0 +1,48 @@
+#include <iostream>
+#include <vector>
+#include <cmath> 
+#include <algorithm>
+
+/**
+ * Jump search function.
+ * 
+ * @param v Sorted vector on which the search will be performed.
+ * @param x Element to be searched.
+ * @return Element index if found; -1 otherwise.
+ */ 
+int jumpSearch(const std::vector<long int> &v, long int x) {
+    int n = v.size(); // number of elements
+    int jump = std::sqrt(n); // block size to jump
+
+    // search for the block the element may be in
+    int prev = 0;
+    while(jump < n && v[jump] <= x) {
+        prev = jump; // jump to next block
+        jump += std::sqrt(n);
+        if(prev >= n) return -1; // vector size exceeded
+    }
+
+    // linear search through the block
+    while(prev < jump) {
+        if(v[prev] == x) return prev; // element found
+        prev++;
+    }
+
+    return -1; // not found
+}
+
+/**
+ * Driver code.
+ */ 
+int main() {
+    // sorted vector on which the search will be performed; [0, 30]
+    std::vector<long int> v = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30};
+    long int x = 7; // element to be searched
+    int index = jumpSearch(v, x);
+
+    if(index != -1) std::cout << "Element found at index " << index;
+        else std::cout << "Element not found";
+    std::cout << std::endl;
+
+    return 0;
+}