Find the contiguous subarray within an array (containing at least one number) which has the largest product.

For example, given the array [2,3,-2,4],
the contiguous subarray [2,3] has the largest product = 6.

很显然是一个动态规划的问题,找到递归表达式就可以了,考虑到会有负负相乘的问题,所以应该维持一个最大的值以及一个最小的值,递归表达式如下所示:

 maxLocal[i + ] = max(max(maxLocal[i] * nums[i + ], minLocal[i] * nums[i + ]), nums[i + ]);
minLocal[i + ] = min(min(maxLocal[i] * nums[i + ], minLocal[i] * nums[i + ]), nums[i + ]);
maxGlobal[i + ] = max(maxGlobal[i], maxLocal[i + ]);

代码如下所示:

 class Solution {
public:
int maxProduct(vector<int>& nums) {
int sz = nums.size();
if (sz == )return ;
if (sz == )return nums[];
int maxP, minP, a, b, ret;
ret = maxP = minP = a = b = nums[];
for (int i = ; i < sz; ++i){
a = max(maxP * nums[i], minP * nums[i]);
b = min(maxP * nums[i], minP * nums[i]);
maxP = max(a, nums[i]);
minP = min(b, nums[i]);
ret = max(maxP, ret);
}
return ret;
} };

java版本的如下所示,注意使用两个中间变量的原因是防止maxVal先直接更新了之后又被minVal所误用:

 public class Solution {
public int maxProduct(int[] nums) {
int maxVal, minVal, ret, tmpMax, tmpMin;
maxVal = minVal = ret = tmpMax = tmpMin = nums[0];
for(int i = 1; i < nums.length; ++i){
tmpMax = Math.max(maxVal * nums[i], minVal * nums[i]);
tmpMin = Math.min(maxVal * nums[i], minVal * nums[i]);
maxVal = Math.max(tmpMax, nums[i]);
minVal = Math.min(tmpMin, nums[i]);
ret = Math.max(maxVal, ret);
}
return ret;
}
}

LeetCode OJ:Maximum Product Subarray(子数组最大乘积)的更多相关文章

  1. 【LeetCode】Maximum Product Subarray 求连续子数组使其乘积最大

    Add Date 2014-09-23 Maximum Product Subarray Find the contiguous subarray within an array (containin ...

  2. C#解leetcode 152. Maximum Product Subarray

    Find the contiguous subarray within an array (containing at least one number) which has the largest ...

  3. 求连续最大子序列积 - leetcode. 152 Maximum Product Subarray

    题目链接:Maximum Product Subarray solutions同步在github 题目很简单,给一个数组,求一个连续的子数组,使得数组元素之积最大.这是求连续最大子序列和的加强版,我们 ...

  4. [LeetCode] 152. Maximum Product Subarray 求最大子数组乘积

    Given an integer array nums, find the contiguous subarray within an array (containing at least one n ...

  5. LeetCode之Maximum Product Subarray

    1.(原文)问题描述 Find the contiguous subarray within an array (containing at least one number) which has t ...

  6. [leetcode]152. Maximum Product Subarray最大乘积子数组

    Given an integer array nums, find the contiguous subarray within an array (containing at least one n ...

  7. LeetCode 152. Maximum Product Subarray (最大乘积子数组)

    Find the contiguous subarray within an array (containing at least one number) which has the largest ...

  8. [leetCode][001] Maximum Product Subarray

    题目: Find the contiguous subarray within an array (containing at least one number) which has the larg ...

  9. Java for LeetCode 152 Maximum Product Subarray

    Find the contiguous subarray within an array (containing at least one number) which has the largest ...

  10. leetcode 152. Maximum Product Subarray --------- java

    Find the contiguous subarray within an array (containing at least one number) which has the largest ...

随机推荐

  1. JVM虚拟机—JVM的类加载机制

    1 什么是类的加载 类的加载指的是将类的.class文件中的二进制数据读入到内存中,将其放在运行时数据区的方法区内,然后在堆区创建一个java.lang.Class对象,用来封装类在方法区内的数据结构 ...

  2. NHibernate & INotifyPropertyChanged

    One of the things that make NHibernate easy to use is that it fully support the POCO model. But one ...

  3. 11 Spring框架 SpringDAO的JdbcTemplate

    上几个章节我们探讨了Spring的IoC和AOP,这是Spring的重点,但是Spring对jdbc的支持同样我们也不能忘记,毕竟我们还要通过Spring来管理DAO框架(例如Hibernate或者M ...

  4. cdoj1337郭大侠与阴阳家

    地址:http://acm.uestc.edu.cn/#/problem/show/1337 思路: 郭大侠与阴阳家 Time Limit: 3000/4000MS (Java/Others)     ...

  5. 跟着实例学习ZooKeeper的用法: 分布式锁

    锁 分布式的锁全局同步, 这意味着任何一个时间点不会有两个客户端都拥有相同的锁. 可重入锁Shared Reentrant Lock 首先我们先看一个全局可重入的锁. Shared意味着锁是全局可见的 ...

  6. 【Head First Servlets and JSP】笔记 25:JSTL 参考

    <%@ page contentType="text/html;charset=UTF-8" language="java" %> <%@ t ...

  7. MySQL Binlog解析(2)

    一.TABLE_MAP_EVENT Used for row-based binary logging beginning with MySQL 5.1.5.The TABLE_MAP_EVENT d ...

  8. maven项目在eclipse的library中没有Maven Dependencies

    今天使用maven创建了一个多模块的项目,在分别创建完父项目和各个子模块后,编译父项目的时候,父项目工程目录上出现了一堆红叉叉,点进去一看,是找不到依赖的类,但是pom文件中相应jar的depende ...

  9. 关于ENABLE_BITCODE

    pod 'TSVoiceConverter' 如果,设置了工程target的ENABLE_BITCODE为NO.但是,在真机上运行时,仍然提示类似于如下错误: URGENT: all bitcode ...

  10. Find Min In Rotated Sorted Array,寻找反转序列中最小的元素。

    问题描述:寻找反转序列中最小的元素. 算法分析:和寻找某个数是一个道理,还是利用二分查找,总体上分两种情况.nums[left]<=nums[mid],else.但是,在截取子序列的时候,有可能 ...