feat: Revised the book (#978)

* Sync recent changes to the revised Word.

* Revised the preface chapter

* Revised the introduction chapter

* Revised the computation complexity chapter

* Revised the chapter data structure

* Revised the chapter array and linked list

* Revised the chapter stack and queue

* Revised the chapter hashing

* Revised the chapter tree

* Revised the chapter heap

* Revised the chapter graph

* Revised the chapter searching

* Reivised the sorting chapter

* Revised the divide and conquer chapter

* Revised the chapter backtacking

* Revised the DP chapter

* Revised the greedy chapter

* Revised the appendix chapter

* Revised the preface chapter doubly

* Revised the figures

codes/javascript/chapter_backtracking/n_queens.js

@@ -16,7 +16,7 @@ function backtrack(row, n, state, res, cols, diags1, diags2) {
         // 计算该格子对应的主对角线和副对角线
         const diag1 = row - col + n - 1;
         const diag2 = row + col;
-        // 剪枝：不允许该格子所在列、主对角线、副对角线存在皇后
+        // 剪枝：不允许该格子所在列、主对角线、副对角线上存在皇后
         if (!cols[col] && !diags1[diag1] && !diags2[diag2]) {
             // 尝试：将皇后放置在该格子
             state[row][col] = 'Q';
@@ -35,8 +35,8 @@ function nQueens(n) {
     // 初始化 n*n 大小的棋盘，其中 'Q' 代表皇后，'#' 代表空位
     const state = Array.from({ length: n }, () => Array(n).fill('#'));
     const cols = Array(n).fill(false); // 记录列是否有皇后
-    const diags1 = Array(2 * n - 1).fill(false); // 记录主对角线是否有皇后
-    const diags2 = Array(2 * n - 1).fill(false); // 记录副对角线是否有皇后
+    const diags1 = Array(2 * n - 1).fill(false); // 记录主对角线上是否有皇后
+    const diags2 = Array(2 * n - 1).fill(false); // 记录副对角线上是否有皇后
     const res = [];
 
     backtrack(0, n, state, res, cols, diags1, diags2);