Merge pull request #2383 from Relsola/master

Update 0084.柱状图中最大的矩形 变量名错误修复和可读性优化，0200.岛屿数量 新增TS深度搜索优先解法

problems/0084.柱状图中最大的矩形.md

@@ -515,27 +515,31 @@ func largestRectangleArea(heights []int) int {
 var largestRectangleArea = function(heights) {
     const len = heights.length;
     const minLeftIndex = new Array(len);
-    const maxRigthIndex = new Array(len);
+    const maxRightIndex = new Array(len);
     // 记录每个柱子 左边第一个小于该柱子的下标
     minLeftIndex[0] = -1; // 注意这里初始化，防止下面while死循环
     for(let i = 1; i < len; i++) {
         let t = i - 1;
         // 这里不是用if，而是不断向左寻找的过程
-        while(t >= 0 && heights[t] >= heights[i]) t = minLeftIndex[t];
+        while (t >= 0 && heights[t] >= heights[i]) {
+			t = minLeftIndex[t];
+		}
         minLeftIndex[i] = t;
     }
     // 记录每个柱子 右边第一个小于该柱子的下标
-    maxRigthIndex[len - 1] = len; // 注意这里初始化，防止下面while死循环
+    maxRightIndex[len - 1] = len; // 注意这里初始化，防止下面while死循环
     for(let i = len - 2; i >= 0; i--){
         let t = i + 1;
         // 这里不是用if，而是不断向右寻找的过程
-        while(t < len && heights[t] >= heights[i]) t = maxRigthIndex[t];
+        while (t <= n && heights[t] > heights[i]) {
-        maxRigthIndex[i] = t;
+			t = maxRightIndex[t];
+		}
+        maxRightIndex[i] = t;
     }
     // 求和
     let maxArea = 0;
     for(let i = 0; i < len; i++){
-        let sum = heights[i] * (maxRigthIndex[i] - minLeftIndex[i] - 1);
+        let sum = heights[i] * (maxRightIndex[i] - minLeftIndex[i] - 1);
         maxArea = Math.max(maxArea , sum);
     }
     return maxArea;
@@ -544,23 +548,33 @@ var largestRectangleArea = function(heights) {
 //单调栈
 var largestRectangleArea = function(heights) {
 	let maxArea = 0;
-    const stack = [];
+	const stack = [0];
-    heights = [0,...heights,0]; // 数组头部加入元素0 数组尾部加入元素0
+	heights.push(0);
-    for(let i = 0; i < heights.length; i++){
+	const n = heights.length;
-        if(heights[i] > heights[stack[stack.length-1]]){ // 情况三
+
+	for (let i = 1; i < n; i++) {
+		let top = stack.at(-1);
+        // 情况三
+		if (heights[top] < heights[i]) {
 			stack.push(i);
-        } else if(heights[i] === heights[stack[stack.length-1]]){ // 情况二
+		}
+        // 情况二
+		if (heights[top] === heights[i]) {
 			stack.pop(); // 这个可以加，可以不加，效果一样，思路不同
 			stack.push(i);
-        } else { // 情况一
+		}
-            while(heights[i] < heights[stack[stack.length-1]]){// 当前bar比栈顶bar矮
+        // 情况一
-                const stackTopIndex = stack.pop();// 栈顶元素出栈，并保存栈顶bar的索引
+		if (heights[top] > heights[i]) {
-                let w = i - stack[stack.length -1] - 1;
+			while (stack.length > 0 && heights[top] > heights[i]) {
-                let h = heights[stackTopIndex]
+                // 栈顶元素出栈，并保存栈顶bar的索引
+				const h = heights[stack.pop()];
+				const left = stack.at(-1) ?? -1;
+				const w = i - left - 1;
                 // 计算面积，并取最大面积
 				maxArea = Math.max(maxArea, w * h);
+				top = stack.at(-1);
 			}
-            stack.push(i);// 当前bar比栈顶bar高了，入栈
+			stack.push(i);
 		}
 	}
 	return maxArea;

problems/0200.岛屿数量.广搜版.md

@@ -276,6 +276,52 @@ var numIslands = function (grid) {
 };
 ```
 
+### TypeScript
+
+```TypeScript
+function numIslands2(grid: string[][]): number {
+	// 四个方向
+	const dir: number[][] = [[0, 1], [1, 0], [-1, 0], [0, -1]];
+	const [m, n]: [number, number] = [grid.length, grid[0].length];
+
+	function dfs(grid: string[][], visited: boolean[][], x: number, y: number) {
+		const queue: number[][] = [[x, y]];
+		while (queue.length !== 0) {
+			//取出队列头部元素
+			const top: number[] = queue.shift()!;
+			for (let i = 0; i < 4; i++) {
+				const nextX: number = top[0] + dir[i][0];
+				const nextY: number = top[1] + dir[i][1];
+				// 越界了，直接跳过
+				if (nextX < 0 || nextX >= m || nextY < 0 || nextY >= n) {
+					continue;
+				}
+				if (!visited[nextX][nextY] && grid[nextX][nextY] === '1') {
+					queue.push([nextX, nextY]);
+					// 只要加入队列立刻标记
+					visited[nextX][nextY] = true;
+				}
+			}
+		}
+	}
+
+	const visited: boolean[][] = Array.from({ length: m }, _ => new Array(n).fill(false));
+
+	let result = 0;
+	for (let i = 0; i < m; i++) {
+		for (let k = 0; k < n; k++) {
+			if (!visited[i][k] && grid[i][k] === '1') {
+				++result; // 遇到没访问过的陆地，+1
+				visited[i][k] = true;
+				dfs(grid, visited, i, k); // 将与其链接的陆地都标记上 true
+			}
+		}
+	}
+	return result;
+}
+```
+
+
 ### Rust
 
 ```rust

problems/0200.岛屿数量.深搜版.md

@@ -346,6 +346,46 @@ var numIslands = function (grid) {
 };
 ```
 
+### TypeScript
+
+```TypeScript
+function numIslands(grid: string[][]): number {
+	// 四个方向
+	const dir: number[][] = [[0, 1], [1, 0], [-1, 0], [0, -1]];
+	const [m, n]: [number, number] = [grid.length, grid[0].length];
+
+	function dfs(grid: string[][], visited: boolean[][], x: number, y: number) {
+		for (let i = 0; i < 4; i++) {
+			let nextX: number = x + dir[i][0];
+			let nextY: number = y + dir[i][1];
+			// 越界了，直接跳过
+			if (nextX < 0 || nextX >= m || nextY < 0 || nextY >= n) {
+				continue;
+			}
+			// 没有访问过同时是陆地
+			if (!visited[nextX][nextY] && grid[nextX][nextY] === '1') {
+				visited[nextX][nextY] = true;
+				dfs(grid, visited, nextX, nextY);
+			}
+		}
+	}
+
+	const visited: boolean[][] = Array.from({ length: m }, _ => new Array(n).fill(false));
+
+	let result: number = 0;
+	for (let i = 0; i < m; i++) {
+		for (let k = 0; k < n; k++) {
+			if (!visited[i][k] && grid[i][k] === '1') {
+				++result; // 遇到没访问过的陆地，+1
+				visited[i][k] = true;
+				dfs(grid, visited, i, k); // 将与其链接的陆地都标记上 true
+			}
+		}
+	}
+	return result;
+}
+```
+
 ### Go
 
 ```go