[最長下降子序列+nlog(n)]北大 POJ 1548 Robots

[cpp] 
/* THE PROGRAM IS MADE BY PYY */ 
/*----------------------------------------------------------------------------//
    Copyright (c) 2012 panyanyany All rights reserved.
 
    URL   : http://poj.org/problem?id=1548
    Name  : 1548 Robots
 
    Date  : Monday, July 9, 2012
    Time Stage : half an hour
 
    Result:
10405836    panyanyany
1548
Accepted    172K    0MS C++
1775B   2012-07-09 13:02:39
 
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    (24*25) 
 
#define L(x)    ((x)<<1) 
#define R(x)    (((x)<<1)|1) 
#define M(x, y) (((x)+(y)) >> 1) 
 
#define DB    // 
 
struct NODE { 
    int x, y; 
}; 
 
bool cmp(const NODE &lhs, const NODE &rhs) 
{ 
    if (lhs.x == rhs.x) 
        return lhs.y < rhs.y; 
    return lhs.x < rhs.x; 
} 
 
NODE a[MAXN]; 
int order[MAXN]; 
 
int LDesS(NODE a[], int n) 
{ 
    int i, r, l, len, m; 
    MEM(order, 0); 
    sort(a, a+n, cmp); 
    len = 1; 
    for (i = 0; i < n; ++i) 
    { 
        l = 1; 
        r = len; 
        while (l <= r) 
        { 
            m = (l + r) >> 1; 
            if (order[m] > a[i].y) 
                l = m + 1; 
            else 
                r = m - 1; 
        } 
 
        if (order[l] < a[i].y) 
            order[l] = a[i].y; 
        len = max(len, l); 
    } 
    return len; 
} 
 
int main() 
{ 
    int x, y, n; 
    n = 0; 
    while (scanf("%d %d", &x, &y) != EOF) 
    { 
        if (x == -1 && y == -1) 
            break; 
 
        if (x != 0 && y != 0) 
        { 
            a[n].x = x; 
            a[n].y = y; 
            ++n; 
        }   www.2cto.com
        else 
        { 
            printf("%d\n", LDesS(a, n)); 
            n = 0; 
        } 
    } 
    return 0; 
} 
作者：panyanyany