【最大且最长子序列和】杭电 hdu 1003 Max Sum

第一个，一开始做的，比较杂乱：

/* THE PROGRAM IS MADE BY PYY */
/*----------------------------------------------------------------------------//
    Copyright (c) 2012 panyanyany All rights reserved.

    URL   : http://acm.hdu.edu.cn/showproblem.php?pid=1003
    Name  : 1003 Max Sum

    Date  : Thursday, July 05, 2012
    Time Stage : 1 hour

    Result:
6132517	2012-07-05 11:39:32	Accepted	1003
0MS	1008K	1950 B
C++	pyy


Test Data :

Review :

//----------------------------------------------------------------------------*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <vector>

#include <algorithm>
#include <iostream>
#include <queue>
#include <set>
#include <string>

using namespace std ;

#define MEM(a, v)        memset (a, v, sizeof (a))    // a for address, v for value
#define max(x, y)        ((x) > (y) ? (x) : (y))
#define min(x, y)        ((x) < (y) ? (x) : (y))

#define INF     (0x3f3f3f3f)
#define MAXN	100009

#define L(x)	((x)<<1)
#define R(x)	(((x)<<1)|1)
#define M(x, y)	(((x)+(y)) >> 1)

#define DB    /##/
typedef __int64	LL;

int sum[MAXN], v[MAXN], s, t, head, tail, n, tcase;


int main()
{
	int i, j, MaxSum, FinSum;

	while (scanf("%d", &tcase) != EOF)
	{
		for (j = 1; j <= tcase; ++j)
		{
			scanf("%d", &n);
			for (i = 0; i < n; ++i)
			{
				scanf("%d", v+i);
				if(0 == i)
				{
					FinSum = sum[i] = v[i];
					s = t = head = tail = i;
				}
				else
				{
					if (sum[i-1] < 0)
					{
						head = tail = i;
						sum[i] = v[i];
					}
					else
					{
						int tmp = sum[i-1] + v[i];
//						if (tmp >= 0)//只有大于0的值才可能+后面的数变成更大的数
//						{
							sum[i] = tmp;
							tail = i;
//						}
/*						else// 若加起来的值为负数，则不如不加
						{
							sum[i] = v[i];
							head = tail = i;
						}
*/
					}
					if (FinSum < sum[i])
					{
						s = head;
						t = tail;
						FinSum = sum[i];
					}
				}
			}
			printf("Case %d:\n%d %d %d\n", j, FinSum, s+1, t+1);
			if (j < tcase)
				putchar('\n');
		}
	}

	return 0;
}

第二个，修改过的，参考了别人的代码：

/* THE PROGRAM IS MADE BY PYY */
/*----------------------------------------------------------------------------//
    Copyright (c) 2012 panyanyany All rights reserved.

    URL   : 
    Name  : 

    Date  : Thursday, July 05, 2012
    Time Stage : 

    Result:
6132607	2012-07-05 12:00:59	Accepted	1003
0MS	616K	1623 B
C++	pyy


Test Data :

Review :

//----------------------------------------------------------------------------*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <vector>

#include <algorithm>
#include <iostream>
#include <queue>
#include <set>
#include <string>

using namespace std ;

#define MEM(a, v)        memset (a, v, sizeof (a))    // a for address, v for value
#define max(x, y)        ((x) > (y) ? (x) : (y))
#define min(x, y)        ((x) < (y) ? (x) : (y))

#define INF     (0x3f3f3f3f)
#define MAXN	100009

#define L(x)	((x)<<1)
#define R(x)	(((x)<<1)|1)
#define M(x, y)	(((x)+(y)) >> 1)

#define DB    /##/
typedef __int64	LL;

int v[MAXN], s, t, head, n, tcase;


int main()
{
	int i, j, FinSum, CurSum;

	while (scanf("%d", &tcase) != EOF)
	{
		for (j = 1; j <= tcase; ++j)
		{
			scanf("%d", &n);
			FinSum = -100000000;
			CurSum = head = 0;
			for (i = 0; i < n; ++i)
			{
				scanf("%d", v+i);
				CurSum += v[i];
				// 下面两个if不能调换过来，否则将无法处理只有一个负数的情况
				if (FinSum < CurSum)
				{
					FinSum = CurSum;
					s = head;
					t = i;
				}
				if (CurSum < 0)
				{
					CurSum = 0;
					head = i+1;
				}
			}
			printf("Case %d:\n%d %d %d\n", j, FinSum, s+1, t+1);
			if (j < tcase)
				putchar('\n');
		}
	}

	return 0;
}