From b22425c859269c5862149a8f736bcf0c3e5e00eb Mon Sep 17 00:00:00 2001 From: Relsola Date: Mon, 25 Dec 2023 22:55:12 +0800 Subject: [PATCH 1/3] =?UTF-8?q?Update=200084.=E6=9F=B1=E7=8A=B6=E5=9B=BE?= =?UTF-8?q?=E4=B8=AD=E6=9C=80=E5=A4=A7=E7=9A=84=E7=9F=A9=E5=BD=A2=E5=8F=98?= =?UTF-8?q?=E9=87=8F=E5=90=8D=E9=94=99=E8=AF=AF=E4=BF=AE=E5=A4=8D=E5=92=8C?= =?UTF-8?q?=E5=8F=AF=E8=AF=BB=E6=80=A7=E4=BC=98=E5=8C=96?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0084.柱状图中最大的矩形.md | 66 ++++++++++++-------- 1 file changed, 40 insertions(+), 26 deletions(-) diff --git a/problems/0084.柱状图中最大的矩形.md b/problems/0084.柱状图中最大的矩形.md index 97dab4f3..b836705a 100644 --- a/problems/0084.柱状图中最大的矩形.md +++ b/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]; - maxRigthIndex[i] = t; + while (t <= n && heights[t] > heights[i]) { + 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; @@ -543,27 +547,37 @@ var largestRectangleArea = function(heights) { //单调栈 var largestRectangleArea = function(heights) { - let maxArea = 0; - const stack = []; - heights = [0,...heights,0]; // 数组头部加入元素0 数组尾部加入元素0 - for(let i = 0; i < heights.length; i++){ - if(heights[i] > heights[stack[stack.length-1]]){ // 情况三 - stack.push(i); - } else if(heights[i] === heights[stack[stack.length-1]]){ // 情况二 - 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 - const stackTopIndex = stack.pop();// 栈顶元素出栈，并保存栈顶bar的索引 - let w = i - stack[stack.length -1] - 1; - let h = heights[stackTopIndex] + let maxArea = 0; + const stack = [0]; + heights.push(0); + const n = heights.length; + + for (let i = 1; i < n; i++) { + let top = stack.at(-1); + // 情况三 + if (heights[top] < heights[i]) { + stack.push(i); + } + // 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); + } + // 情况一 + if (heights[top] > heights[i]) { + while (stack.length > 0 && heights[top] > heights[i]) { + // 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); - } - stack.push(i);// 当前bar比栈顶bar高了，入栈 - } - } - return maxArea; + maxArea = Math.max(maxArea, w * h); + top = stack.at(-1); + } + stack.push(i); + } + } + return maxArea; }; //单调栈 简洁 From 2368a622773736ee74f8d432f8cb891ec2f3c74c Mon Sep 17 00:00:00 2001 From: Relsola Date: Wed, 27 Dec 2023 19:23:37 +0800 Subject: [PATCH 2/3] =?UTF-8?q?Update=200200.=E5=B2=9B=E5=B1=BF=E6=95=B0?= =?UTF-8?q?=E9=87=8F.=E6=B7=B1=E6=90=9C=E7=89=88.md=20=E6=96=B0=E5=A2=9ETS?= =?UTF-8?q?=E6=B7=B1=E5=BA=A6=E6=90=9C=E7=B4=A2=E4=BC=98=E5=85=88=E8=A7=A3?= =?UTF-8?q?=E6=B3=95?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0200.岛屿数量.深搜版.md | 40 +++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/problems/0200.岛屿数量.深搜版.md b/problems/0200.岛屿数量.深搜版.md index 43eb66e1..a4b93c3d 100644 --- a/problems/0200.岛屿数量.深搜版.md +++ b/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 From 22ebe65604be3b53c53503f64d1aa7ed3b0b220f Mon Sep 17 00:00:00 2001 From: Relsola Date: Wed, 27 Dec 2023 19:51:37 +0800 Subject: [PATCH 3/3] =?UTF-8?q?Update=20200.=E5=B2=9B=E5=B1=BF=E6=95=B0?= =?UTF-8?q?=E9=87=8F.=E5=B9=BF=E6=90=9C=E7=89=88.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0200.岛屿数量.广搜版.md | 46 +++++++++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/problems/0200.岛屿数量.广搜版.md b/problems/0200.岛屿数量.广搜版.md index e8ed60db..a7dd117b 100644 --- a/problems/0200.岛屿数量.广搜版.md +++ b/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