cf340D Bubble Sort Graph

link:http://codeforces.com/problemset/problem/340/D

感觉很好的一道题目。

认真思考，发现，逆序的数字对一定有边相连。所以，题目要求没有边相连的最大的集合的点的个数，其实就是找原来的序列的最长上升子序列！

/*
 *       Filename:  tourist.cpp
 *        Created:  09/01/2013 09:07:05 AM
 *         Author:  liuxueyang (lxy), zypz457@sina.com
 *   Organization:  Hunnan University
 */

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <cctype>
#include <algorithm>
#include <queue>
#include <deque>
#include <queue>
#include <list>
#include <map>
#include <set>
#include <vector>
#include <utility>
#include <functional>
#include <fstream>
#include <iomanip>
#include <sstream>
#include <numeric>
#include <cassert>
#include <ctime>
#include <iterator>
const int INF = 0x3f3f3f3f;
const int MOD = 1e9+7;
using namespace std;
int touch[100009];
int main ( int argc, char *argv[] )
{
#ifndef ONLINE_JUDGE
    freopen("in.txt","r",stdin);
#endif
    ios::sync_with_stdio(false);
    int n;
    while (~scanf("%d", &n)) {
        touch[0] = -1;
        int tmp, top = 0;
        for (int i = 0; i < n; ++i) {
            scanf("%d", &tmp);
            if (tmp > touch[top]) {
                touch[++top] = tmp;
            } else {
                int pos = lower_bound(touch+1, touch+1+top, tmp) - touch;
                touch[pos] = tmp;
            }
        }
        printf("%d\n", top);
    }
        return EXIT_SUCCESS;
}                /* ----------  end of function main  ---------- */

好几天了，还是补上题解吧。

嗨，中村。