add quick sort

Author: jamesmarva

code/examples/sort/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "sort"
+version = "0.1.0"
+authors = ["jameskk <[email protected]>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

code/examples/sort/src/main.rs

@@ -0,0 +1,52 @@
+fn main() {
+    let mut a = [12,232,234,2,34,234,234,2,34,2,34,234,234,2,34,234,2,34,2,34,234,2,34,2];
+    quick(&mut a);
+    for item in &a {
+        println!("{}", item);
+    }
+}
+
+fn quick(arr: &mut [i32]) {
+    quick_sort(arr, 0, (arr.len() - 1) as usize);
+}
+
+fn quick_sort(arr: &mut [i32], start: usize, end: usize) {
+    if start >= end {
+        return;
+    }
+    let pivot_idx = partition(arr, start, end);
+    quick_sort(arr, start, pivot_idx - 1);
+    quick_sort(arr, pivot_idx + 1, end);
+}
+
+fn partition(arr: &mut [i32], start: usize, end: usize) -> usize {
+    let pivot_val = arr[start];
+    let mut left = start;
+    let mut right = end + 1;
+    loop {
+        loop {
+            left += 1;
+            if arr[left] > pivot_val || left == end {
+                break;
+            }
+        }
+        loop {
+            right -= 1;
+            if arr[right] <= pivot_val || right == start {
+                break;
+            }
+        }
+        if left >= right {
+            break;
+        }
+        swap(arr, left, right);
+    }
+    swap(arr, start, right);
+    right
+}
+
+fn swap(arr: &mut [i32], a: usize, b: usize) {
+    let tmp = arr[a];
+    arr[a] = arr[b];
+    arr[b] = tmp;
+}