ZOJ 1986 Bridging Signals

题目链接：http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=986

最长上升子序列……

 1 #include <cstdio>

 2 #include <cstring>

 3 

 4 const int MAXN = 40000 + 10;

 5 

 6 int n;

 7 int num[MAXN];

 8 int stack[MAXN];

 9 

10 int Bsearch( int x, int y, int v )

11 {

12     int m;

13     while ( x < y )

14     {

15         m = x + (y - x) / 2;

16         if ( stack[m] == v ) return m;

17         else if ( stack[m] > v ) y = m;

18         else x = m + 1;

19     }

20     return m;

21 }

22 

23 int DP()

24 {

25     int top = 0;

26 

27     stack[ ++top ] = num[0];

28 

29     for ( int i = 1; i < n; i++ )

30     {

31         if ( num[i] > stack[top] ) stack[ ++top ] = num[i];

32         else

33         {

34             int temp = Bsearch( 1, top + 1, num[i] );

35             if (stack[temp] > num[i])

36                 stack[temp] = num[i];

37             else stack[temp + 1] = num[i];

38         }

39     }

40 

41     return top;

42 }

43 

44 int main()

45 {

46     int T;

47     scanf("%d", &T);

48     while ( T-- )

49     {

50         scanf( "%d", &n );

51         for ( int i = 0; i < n; i++ )

52             scanf( "%d", &num[i] );

53 

54         printf( "%d\n", DP() );

55     }

56     return 0;

57 }