对于数组A[0,1,2,3,4,...,k],求得0<=i < j < k,且使得A[j] - A[i]为最大值。


#include <iostream>
#include <vector>
#include "math.h"
using namespace std;

class Solution{
    public:
    bool maxSum(vector<int> & array, int & result){
        if(array.size() <= 1)
            return false;
        else if(array.size() == 2){
            result = array[1] - array[0];
            return true;
        }
        else{
            int preMin = array[0], tempMax = 0;
            for(int i = 1; i < array.size(); i ++){
                if(array[i] < preMin){
                    preMin = array[i];
                }
                else
                    tempMax = max(tempMax, array[i] - preMin);
            }
            result = tempMax;
            return true;
        }
    }
};

int main() {
	cout  << "test\n";
	Solution sol;
	int arrayTemp[] = {2, 3, 8, 1, 7, 9};
	vector<int> array(arrayTemp, arrayTemp + 6);
	int result;
	sol.maxSum(array,result);
	cout << result << endl;
	return 0;
}