人人都来写算法 之 求子数组的最大和

题目：

求子数组的最大和：输入一个整数数组，数组中有正有负，求所有子数组的和的最大值。

#include <iostream>

using std::cout;

using std::endl;

bool FindGreatestSumOfSubArray(int data[], int length, int &greatestSum)

{

if((data == NULL)||(length==0))

{

return false;

}

int curSum = 0;

greatestSum = 0;

for(int i=0; i<length; ++i)

{

curSum = curSum + data[i];

if(curSum<0)

{

curSum=0;

}

if(curSum>greatestSum)

{

greatestSum = curSum;

}

}

// if input value is all negative number, then find the biggest negative number.

if(greatestSum == 0)

{

greatestSum = data[0];

for(int i=1; i<length; ++i)

{

if(data[i]>greatestSum)

{

greatestSum = data[i];

}

}

}

return true;

}

int main()

{

const int count = 10;

int a[count] = {1, -8, 6, 3, -1, 5, 7, -2, 0, 1};

//int a[10] = {1, -2, 3, 10, -4, 7, 2, 0, -5, 0};

int subsum = 0;

if(FindGreatestSumOfSubArray(a,count, subsum))

{

cout<<"biggest sub sum is: "<<subsum<<endl;

}

else

{

cout<<"Error>>>input value is not right."<<endl;

}

getchar();

}