translation: optimize translation for selection sort (#1600)

* optimize translation for selection sort

* update selection sort translation

en/docs/chapter_sorting/selection_sort.md

@@ -1,14 +1,14 @@
 # Selection sort
 
-<u>Selection sort</u> works on a very simple principle: it starts a loop where each iteration selects the smallest element from the unsorted interval and moves it to the end of the sorted interval.
+<u>Selection sort</u> works on a very simple principle: it uses a loop where each iteration selects the smallest element from the unsorted interval and moves it to the end of the sorted section.
 
-Suppose the length of the array is $n$, the algorithm flow of selection sort is as shown in the figure below.
+Suppose the length of the array is $n$, the steps of selection sort is shown in the figure below.
 
 1. Initially, all elements are unsorted, i.e., the unsorted (index) interval is $[0, n-1]$.
 2. Select the smallest element in the interval $[0, n-1]$ and swap it with the element at index $0$. After this, the first element of the array is sorted.
 3. Select the smallest element in the interval $[1, n-1]$ and swap it with the element at index $1$. After this, the first two elements of the array are sorted.
 4. Continue in this manner. After $n - 1$ rounds of selection and swapping, the first $n - 1$ elements are sorted.
-5. The only remaining element is necessarily the largest element and does not need sorting, thus the array is sorted.
+5. The only remaining element is subsequently the largest element and does not need sorting, thus the array is sorted.
 
 === "<1>"
     ![Selection sort process](selection_sort.assets/selection_sort_step1.png)
@@ -51,7 +51,7 @@ In the code, we use $k$ to record the smallest element within the unsorted inter
 
 ## Algorithm characteristics
 
-- **Time complexity of $O(n^2)$, non-adaptive sort**: There are $n - 1$ rounds in the outer loop, with the unsorted interval length starting at $n$ in the first round and decreasing to $2$ in the last round, i.e., the outer loops contain $n$, $n - 1$, $\dots$, $3$, $2$ inner loops respectively, summing up to $\frac{(n - 1)(n + 2)}{2}$.
+- **Time complexity of $O(n^2)$, non-adaptive sort**: There are $n - 1$ iterations in the outer loop, with the length of the unsorted section starting at $n$ in the first iteration and decreasing to $2$ in the last iteration, i.e., each outer loop iterations contain $n$, $n - 1$, $\dots$, $3$, $2$ inner loop iterations respectively, summing up to $\frac{(n - 1)(n + 2)}{2}$.
 - **Space complexity of $O(1)$, in-place sort**: Uses constant extra space with pointers $i$ and $j$.
 - **Non-stable sort**: As shown in the figure below, an element `nums[i]` may be swapped to the right of an equal element, causing their relative order to change.