Splay入门题目 [HNOI2002]营业额统计

题目链接：http://www.lydsy.com/JudgeOnline/problem.php?id=1588

这道题貌似很多中做法，我先是用multiset交了一发，然后又写了一发splay。

multiset做法，这个其实就是二分了，只是用set来保持加入一个元素时保持有序

 1 #include <set>

 2 #include <map>

 3 #include <cmath>

 4 #include <ctime>

 5 #include <queue>

 6 #include <stack>

 7 #include <cctype>

 8 #include <cstdio>

 9 #include <string>

10 #include <vector>

11 #include <cstdlib>

12 #include <cstring>

13 #include <iostream>

14 #include <algorithm>

15 using namespace std;

16 typedef unsigned long long ull;

17 typedef long long ll;

18 const int inf = 0x3f3f3f3f;

19 const double eps = 1e-8;

20 multiset<int>S;

21 multiset<int>::iterator it;

22 int main(void)

23 {

24     #ifndef ONLINE_JUDGE

25         freopen("in.txt","r",stdin);

26     #endif

27     int n;

28     while (~scanf ("%d",&n))

29     {

30         int ans = 0;

31         S.clear();

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

33         {

34             int x;

35             if (scanf ("%d",&x) == EOF)

36                 x = 0;

37             it = S.lower_bound(x);

38             if (it == S.begin())

39                 ans += abs(*it-x);

40             else

41             {

42                 int s1 = *it;

43                 int s2 = *--it;

44                 ans +=  min(abs(s1 - x),abs(s2 - x));

45             }

46             S.insert(x);

47         }

48         printf("%d\n",ans);

49     }

50     return 0;

51 }

View Code

splay

  1 #include <set>

  2 #include <map>

  3 #include <cmath>

  4 #include <ctime>

  5 #include <queue>

  6 #include <stack>

  7 #include <cctype>

  8 #include <cstdio>

  9 #include <string>

 10 #include <vector>

 11 #include <cstdlib>

 12 #include <cstring>

 13 #include <iostream>

 14 #include <algorithm>

 15 using namespace std;

 16 typedef unsigned long long ull;

 17 typedef long long ll;

 18 const int inf = 0x3f3f3f3f;

 19 const double eps = 1e-8;

 20 template <class T>

 21 inline bool scan_d(T &ret)

 22 {

 23     char c;

 24     int sgn;

 25     if(c=getchar(),c==EOF)

 26         return 0;

 27     while(c!='-'&&(c<'0'||c>'9'))

 28         c=getchar();

 29     sgn = (c=='-')?-1:1;

 30     ret =(c=='-')?0:(c-'0');

 31     while(c=getchar(),c>='0'&&c<='9')

 32         ret=ret*10+(c-'0');

 33     ret*=sgn;

 34     return 1;

 35 }

 36 const int maxn = 1e5+10;

 37 int fa[maxn],son[maxn][2],key[maxn],tot,root;

 38 

 39 

 40 

 41 void addNode(int &r,int father,int k)

 42 {

 43     r = ++tot;

 44     fa[r] = father;

 45     key[r] = k;

 46     son[r][0] = son[r][1] = 0;

 47 }

 48 

 49 void Rotate(int r,int kind)

 50 {

 51     int y = fa[r];

 52     son[y][!kind] = son[r][kind];

 53     fa[son[r][kind]] = y;

 54     if (fa[y])

 55         son[fa[y]][son[fa[y]][1]==y] = r;

 56     son[r][kind] = y;

 57     fa[r] = fa[y];

 58     fa[y] = r;

 59 }

 60 void splay(int r,int goal)

 61 {

 62     while (fa[r] != goal)

 63     {

 64         if (fa[fa[r]] == goal)

 65         {

 66             Rotate(r,son[fa[r]][0] == r);

 67         }

 68         else

 69         {

 70             int y = fa[r];

 71             int kind = (son[fa[y]][0] == y);

 72             if (son[y][kind] == r)

 73             {

 74                 Rotate(r,!kind);

 75                 Rotate(r,kind);

 76             }

 77             else

 78             {

 79                 Rotate(y,kind);

 80                 Rotate(r,kind);

 81             }

 82         }

 83     }

 84     if (goal == 0)

 85         root = r;

 86 }

 87 bool Insert(int k)

 88 {

 89     int r = root;

 90     while (son[r][k > key[r]])

 91     {

 92         if (k == key[r])

 93         {

 94             splay(r,0);

 95             return false;

 96         }

 97         r = son[r][k>key[r]];

 98     }

 99     addNode(son[r][k>key[r]],r,k);

100     splay(son[r][k>key[r]],0);

101     return true;

102 }

103 int get_pre(int r)

104 {

105     int tmp = son[r][0];

106     if (tmp == 0)

107         return inf;

108     while (son[tmp][1])

109         tmp = son[tmp][1];

110     return  key[tmp];

111 }

112 int get_next(int r)

113 {

114     int tmp = son[r][1];

115     if (tmp==0)

116         return inf;

117     while (son[tmp][0])

118         tmp = son[tmp][0];

119     return key[tmp] ;

120 }

121 int main(void)

122 {

123     #ifndef ONLINE_JUDGE

124         freopen("in.txt","r",stdin);

125     #endif

126     int n;

127     while (~scanf ("%d",&n))

128     {

129         tot = 0;

130         root = 0;

131         int ans = 0;

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

133         {

134             int x;

135             if (scanf ("%d",&x) == EOF)

136                 x = 0;

137             if (i == 0)

138             {

139                 ans += x;

140                 addNode(root,0,x);

141             }

142             else

143             {

144                 if (!Insert(x))

145                     continue;

146                 int l = get_pre(root);

147                 int r = get_next(root);

148                 ans += min(abs(x-l),abs(x-r));

149                 //ans += min(l,r);

150             }

151         }

152         printf("%d\n",ans);

153     }

154     return 0;

155 }

View Code