zoukankan      html  css  js  c++  java
  • LeetCode 463. Island Perimeter

    You are given a map in form of a two-dimensional integer grid where 1 represents land and 0 represents water. Grid cells are connected horizontally/vertically (not diagonally). The grid is completely surrounded by water, and there is exactly one island (i.e., one or more connected land cells). The island doesn't have "lakes" (water inside that isn't connected to the water around the island). One cell is a square with side length 1. The grid is rectangular, width and height don't exceed 100. Determine the perimeter of the island.

    Example:

    [[0,1,0,0],
     [1,1,1,0],
     [0,1,0,0],
     [1,1,0,0]]
    
    Answer: 16
    
    

    分析:

    既然要求所有island的周长,那么一个island的周长是4,但是因为重叠部分不计算长度,所以我们要减去上下左右重叠部分的长度。代码如下:

    function caculate(grids) {
        let total = 0;
        for(let outer = 0; outer < grids.length; outer++) {
            for(let inner = 0; inner < grids[outer].length; inner++) {
                if(grids[outer][inner] == 1) {
                    let sum = 4;
                    //left
                    if((inner -1) >= 0 && grids[outer][inner-1] == 1) {
                        sum--;
                    }
                    //right
                    if((inner + 1) < grids[outer].length && grids[outer][inner+1] == 1 ){
                        sum--;
                    }
                    //top
                    if(outer-1 >= 0 && grids[outer-1][inner] == 1){
                        sum--;
                    } 
                    //bottom
                    
                    if(outer +1 <= grids.length-1 && grids[outer +1][inner] == 1){
                        sum--;
                    }
                     total+= sum;
                }
                            
            }
        }
        return total;
    }
    console.log(caculate([[0,1,0,0],[1,1,1,0],[0,1,0,0],[1,1,0,0]]));
  • 相关阅读:
    ADO.NET_01_概述
    我对持久层的一点看法
    浅谈极限编程(XP)和代码重构(Refectoring)
    设计模式_第一篇_开场
    .NET OracleLob 读写操作
    ASP.NET_ASP.NET Cookies
    设计模式_第二篇_策略模式
    Oracle_C# 实现 Oracle Text(全文检索)的一个简单例子
    IKVM.NET_06_用户指南_教程
    ADO.NET_02_DataTable
  • 原文地址:https://www.cnblogs.com/gogolee/p/6656669.html
Copyright © 2011-2022 走看看