[最长公共子序列]杭电 HDU 1423 Greatest Common Increasing Subsequence

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

    URL   :
    Name : 1423 Greatest Common Increasing Subsequence
    Classification : 最长公共子序列

    Date : Wednesday, July 11, 2012
    Time Stage : two hour

    Result:
6178365 2012-07-11 11:46:23 Accepted    1423
15MS    236K    1670 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    (1005)

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

#define DB    //

int a[MAXN], b[MAXN], dp[MAXN];

int GCIS(int n1, int n2)
{
    int i, j, pos;
    MEM(dp, 0);
    for (i = 1; i <= n1; ++i)
    {
        pos = 0;
        for (j = 1; j <= n2; ++j)
        {
            // 遍历b的同时，找出 j 之前最大的公共子序列所在点 pos，并且要使 b[pos] < a[i]
            // 这样，当下一句 b[j]==a[i] 时，就可以直接得到 j 点的最大公共子序列了：dp[pos]+1
            // 像 dp[j-1]+1，或者 dp[j]+1 之类的，都不能保证结果最优。
            if (b[j] < a[i] && dp[pos] < dp[j])
            {
                pos = j;
            }

            if (b[j] == a[i])
                dp[j] = dp[pos] + 1;
        }
    }
    j = 0;
    for (i = 1; i <= n2; ++i)
        j = max(j, dp[i]);

    return j;
}

int main()
{
    int i, n1, n2, tc;
    while (scanf("%d", &tc) != EOF)
    {   www.zzzyk.com
        while (tc--)
        {
            scanf("%d", &n1);
            for (i = 1; i <= n1; ++i)
                scanf("%d", a+i);
            scanf("%d", &n2);
            for (i = 1; i <= n2; ++i)
                scanf("%d", b+i);

            printf("%d\n", GCIS(n1, n2));
            if (tc)
                putchar('\n');
        }
    }
    return 0;
}

作者：panyanyany

补充：软件开发 , C++ ,