最大子数组的O(n)算法

无名小辈-欢迎点评
比分治算法性能更优越的解决最大子数组问题
时间复杂度为O(n)

//头文件 inc.h
#pragma once
#include <iostream>
using namespace std;
class CReslut {
public:
	int max_left;//最大子数组左边界
	int max_right;//最大子数组右边界
	int max_sum;//最大子数组和
	CReslut() {
		max_left = 0;
		max_right = 0;
		max_sum = 0;
	};
};

算法：传入数组地址，数组长度

CReslut Find_MAX_DP(int *A,int length) {
	int max_left = 0;
	int max_right = 0;
	int max_sum = A[0];
	int psum = max_sum;
	int p = max_left;

	for (int i = 0; i < length; i++) {
		if (i > max_right) {
			if (psum > 0)
				psum += A[i];
			else {
				p = i;
				psum = A[i];
			}
		}
		if (A[i] >= 0&& psum >= max_sum) {
			max_left = p;
			max_right = i;
			max_sum = psum;
			psum = max_sum;
		}
	}
	CReslut re;
	re.max_left = max_left;
	re.max_right = max_right;
	re.max_sum = max_sum;
	return re;
}

测试代码：

#include<iostream>
#include "inc.h"
using namespace std;
int main() {
	//测试集
	int* A = new int[16];
	A[0] = 13; A[1] = -3; A[2] = -25; A[3] = 20; A[4] = -3;
	A[5] = -16; A[6] = -23; A[7] = 18; A[8] = 20; A[9] = -7;
	A[10] = 12; A[11] = -5; A[12] = -22; A[13] = 15; A[14] =-4;
	A[15] = 7;
	
	for (int i = 0; i < 16; i++) {
		cout << A[i] << endl;
	}

	CReslut reMy = Find_MAX_DP(A,16);
	cout << "最大子数组和:" << reMy.max_sum << endl;
	cout << "左边界:" << reMy.max_left << endl;
	cout << "右边界:" << reMy.max_right << endl;
	delete[]A;
}

测试结果：