Best Time to Buy and Sell Stock II--疑惑

https://oj.leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/

代码如下时能AC

 class Solution {
 public:
     int maxProfit(vector<int> &prices) {
         int p=;
         for(int i = ; i < prices.size() ; ++i) {
             int delta = prices[i] - prices[i-];
             if(delta >  ) {
                 p += delta;
             }
         }
         return p;
     }
 };

但是，代码如下时却Runtime Error,提示Last executed input:[]

 class Solution {
 public:
     int maxProfit(vector<int> &prices) {
         int p=;
         for(int i = ; i < prices.size()- ; ++i) {
             int delta = prices[i+] - prices[i];
             if(delta >  ) {
                 p += delta;
             }
         }
         return p;
     }
 };

这代码明明跟这段Java是一样的啊。这Java代码也能AC。奇怪。

 public class Solution {
 public int maxProfit(int[] prices) {
     int total = 0;
     for (int i=0; i< prices.length-1; i++) {
         if (prices[i+1]>prices[i]) total += prices[i+1]-prices[i];
     }

     return total;
 }

最后只能是加入一行

  if(prices.size()==) return ;

来保证edge case.

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This problem is solved by Shangrila finally:

Replace prices.size()-1 by int(prices.size())-1. The type of prices.size() is SIZE_T, which is unsigned integer types. -1 could overflow.

answered 9 hours ago by Shangrila (48,010 points)