数组最大子数组和

// maxofArray.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream>
using namespace std;
#define N 11 
int max_sub_array(int &s,int &e,int * a);
int max_sub_array1(int &s,int &e,int * a);
int max_sub_array2(int &s,int &e,int * a);
int main()
{
    int a[N]={31,-41,59,26,0,-53,58,97,-93,-23,84};
    int start,end;
    int sum = max_sub_array1(start,end,a);
    cout << sum << "  "<<start<< " "<<end<< endl;
    return 0;
}
int max_sub_array(int &s,int &e,int * a)
{
    int i=0;
    int j,k =0;
    int b,start,end;
    int sum = 0;
    int max = a[0];
    s = e = start = end = 0;//sºÍeÊÇÕû¸öÊý×éa[0~n]µÄ×î´ó×ӶεÄÆðĩλÖá£startºÍendÊÇÊý×éa[0~i]µÄÆðĩλÖÃ
    for(i = 0;i < N; i++)
    {
        
        for (j=i;j<N;j++){        
            for(k=i;k<=j;k++){
                sum += a[k];
            }
            if(sum > max){
                max = sum;
                start = i;
                end =j;
            }
            sum=0;
        }
    }
    s = start;
    e= end;
    return max;
}
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//´úÂëÈçÏ£º
int max_sub_array1(int &s,int &e,int * a)
{
    int i=0;
    int j,k =0;
    int start,end;
    int sum = 0;
    int max = a[0];
    s = e = start = end = 0;//sºÍeÊÇÕû¸öÊý×éa[0~n]µÄ×î´ó×ӶεÄÆðĩλÖá£startºÍendÊÇÊý×éa[0~i]µÄÆðĩλÖÃ
    for(i = 0;i < N; i++)
    {
        sum=0;
        for (j=i;j<N;j++){        
            sum+=a[j];
            if(sum > max){
                max = sum;
                start = i;
                end =j;
            }
        }
    }
    s = start;
    e= end;
    return max;
}
int max_sub_array2(int &s,int &e,int * a)
{
    int i=0;
    int j =0;
    int b,start,end;
    int sum = 0;
    sum = b = a[0];
    s = e = start = end = 0;//sºÍeÊÇÕû¸öÊý×éa[0~n]µÄ×î´ó×ӶεÄÆðĩλÖá£startºÍendÊÇÊý×éa[0~i]µÄÆðĩλÖá£
    for(i = 1;i<N;i++)
    {
        if(b>0)
        {
            b = b + a[i];
            end = i;
        }
        else
        {
            b = a[i];
            start = end = i;
        }
        if(sum<b)
        {
            sum = b;
            s = start;
            e = end;
        }
    }
    return sum;
}