121:best time to Buy and Sell Stock "array" "two pointers"

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/* Test instructions: An array, the element I represents the price of the stock of day I, only allowed to buy and sell once, for maximum profit *//** * Ideas: Two pointers, one scan the entire array, the other record the minimum value of the scanned element * During      the scan, update the minimum value while updating the maximum profit *      Maximum profit: Max (A[j]-a[i]), J>i */class Solution {public:    int maxprofit (vector<int> &prices) {        int len = Prices.size ();        if (Len <= 1) return 0;        int minn = prices[0];  First pointer: Record the minimum value        int profit = 0;    Maximum profit        for (int i = 1; i < Len; i + +) {   //second pointer, scan entire array            minn = MIN (minn, prices[i]);            Profit = Max (Profit, Prices[i]-Minn);        }        return profit;}    ;

　　

121:best time to Buy and Sell Stock "array" "two pointers"