The best time to buy and buy stocks

The best time to buy and buy stocks

The best time to buy and buy stocks

Description: Suppose there is an array whose I-th element is the price of a given stock on the I-th day. If you are allowed to complete a transaction at most once (for example, a stock transaction), design an algorithm to find the maximum profit.

Example

An array example [3, 2, 3, 1, 2] is provided, and 1 is returned.

 

I just made this question in LintCode. At first, it was because of the for loop nesting problem and the running time timed out. Is the following a substitute?

class Solution {public:    /**     * @param prices: Given an integer array     * @return: Maximum profit     */    int maxProfit(vector<int> &prices) {        // write your code here    /*if(pirces.size()==0){    return 0;}*/        if(prices.size()==0)        return 0;        int max=0,sum=prices.size();        int i,j;        for(i=0;i<sum-1;i++)        {            for(j=0;j<sum-1-i;j++)            {            if(prices[i]<prices[i+j+1]&&max<prices[i+j+1]-prices[i])                max=prices[i+j+1]-prices[i];            }         }    return max;    }};

 

Below I discard a for Loop

class Solution {public:    /**     * @param prices: Given an integer array     * @return: Maximum profit     */    int maxProfit(vector<int> &prices) {        // write your code here    /*if(pirces.size()==0){    return 0;}*/        if(prices.size()==0)        return 0;        int min=prices[0],max=0,sum=prices.size();        for(int i=0;i<sum-1;i++)        {            if(prices[i+1]<min)            {                min=prices[i+1];            }            else            {                if(max<prices[i+1]-min)                max=prices[i+1]-min;            }         }    return max;    }};