HDU 5023 A Corrupt Mayor's Performance Art( 线段树 + 区间更新 + 状态压缩 )

 

HDU 5023 A Corrupt Mayor's Performance Art （线段树 + 状态压缩）

上周网络赛的B题，题目很长但是前面根本没有用
题意：线段树操作

P l r c      将 [l,r] 区间颜色换为 c
Q l r　      查询 [l,r]区间一共有多少种颜色，并按升序输出

[  PS:  初始状态墙壁颜色全部为2， 总共30种颜色  ]


分析①: 考虑到最多30种颜色，可以直接用一个int型的变量来存放状态，32位正好
具体就是用线段树的成段更新，lazy为懒惰标记。注意下Query,详见代码

  1 /* ***********************************************

  2 Problem       :

  3 File Name     :

  4 Author        :

  5 Created Time  :

  6 ************************************************ */

  7 //#define BUG

  8 #include <cstdio>

  9 #include <cstring>

 10 #include <algorithm>

 11 #include <map>

 12 #include <vector>

 13 #include <list>

 14 #include <queue>

 15 #include <ctime>

 16 #include <iostream>

 17 #include <cmath>

 18 #include <set>

 19 #include <string>

 20 using namespace std;

 21 typedef long long LL;

 22 typedef unsigned long long ULL;

 23 #define INF                 0x7fffffff

 24 #define MAX                 0x3f3f3f3f

 25 

 26 #define CLR( a, b )         memset( a, b, sizeof(a) )

 27 #define REP( i, a, b )      for( int i = (a); i < (b); ++i )

 28 #define FOR( i, a, b )      for( int i = (a); i <=(b); ++i )

 29 #define FOD( i, a, b )      for( int i = (a); i >=(b); --i )

 30 #define MID                 ( l + r ) >> 1

 31 #define lson                l, m, o << 1

 32 #define rson                m + 1, r, o << 1 | 1

 33 #define ls                  o << 1

 34 #define rs                  o << 1 | 1

 35 

 36 #define MAXN                1010101

 37 

 38 int lazy[MAXN << 2];

 39 int col[MAXN << 2];

 40 

 41 void PushUp( int o )

 42 {

 43     col[o] = col[ls] | col[rs];

 44 }

 45 

 46 void PushDown( int o )

 47 {

 48     if( lazy[o] )

 49     {

 50         lazy[ls] = lazy[o];

 51         lazy[rs] = lazy[o];

 52         col[ls] = col[rs] = lazy[o];//向下传递并直接修改col的值

 53         lazy[o] = 0;

 54     }

 55 }

 56 

 57 void Build( int l, int r, int o )

 58 {

 59     if( l == r )

 60     {

 61         col[o] = 1 << (2-1);

 62         return;

 63     }

 64     int m = MID;

 65     Build( lson );

 66     Build( rson );

 67     PushUp( o );

 68 }

 69 

 70 void Update( int L, int R, int v, int l, int r, int o )

 71 {

 72     if( L <= l && r <= R )

 73     {

 74         lazy[o] = 1 << v;

 75         col[o] = 1 << v;

 76         return;

 77     }

 78     int m = MID;

 79     PushDown( o );

 80     if(L <= m)  Update( L, R, v, lson );

 81     if(R >  m)  Update( L, R, v, rson );

 82     PushUp( o );

 83 

 84 }

 85 

 86 int Query ( int L , int R , int l , int r , int o )

 87 {

 88     if( L <= l && r <= R ) return col[o];

 89     int m = MID;

 90     PushDown( o );

 91     if ( R <= m ) return Query ( L , R , lson ) ;

 92     if ( m <  L ) return Query ( L , R , rson ) ;

 93 

 94     return Query ( L , R , lson ) | Query ( L , R , rson ) ;

 95 }

 96 

 97 

 98 void Orz()

 99 {

100     int N,M;

101     int l, r, co;

102     char ch;

103     while( ~scanf("%d%d",&N,&M) && (N+M) )

104     {

105         getchar();

106         CLR( col, 0 ), CLR( lazy, 0 );

107         Build(1,N,1);

108         //Update(1,N,1,1,N,1);

109         REP( i,0,M )

110         {

111             ch = getchar();

112             if( ch == 'P' )

113             {

114                 scanf( "%d %d %d", &l, &r, &co );

115                 Update( l, r, co-1, 1, N, 1 );

116             }

117             else

118             {

119                 scanf( "%d %d", &l, &r );

120                 int ans = Query(l,r,1,N,1);

121                 int flag = 0;

122                 REP( i, 0, 30 )

123                 {

124                     if( ans & (1 << i) )

125                     {

126                         if( flag )    printf(" ");

127                         flag = 1;

128                         printf( "%d", i + 1 );

129                     }

130                 }

131                 puts("");

132             }

133             getchar();

134         }

135     }

136 }

137 

138 

139 int main()

140 {

141     #ifdef  BUG

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

143     #endif

144     Orz();

145     return 0;

146 }

代码君

分析②: col[o] 存放当前线段内的颜色，PushDown()向下传递，然后最后也是用二分进行查询，用Hash数组判重，用cnt统计并用ans记录答案。

  1 /* ***********************************************

  2 Problem       :

  3 File Name     :

  4 Author        :

  5 Created Time  :

  6 ************************************************ */

  7 //#define BUG

  8 #include <cstdio>

  9 #include <cstring>

 10 #include <algorithm>

 11 #include <map>

 12 #include <vector>

 13 #include <list>

 14 #include <queue>

 15 #include <ctime>

 16 #include <iostream>

 17 #include <cmath>

 18 #include <set>

 19 #include <string>

 20 using namespace std;

 21 typedef long long LL;

 22 typedef unsigned long long ULL;

 23 #define INF                 0x7fffffff

 24 #define MAX                 0x3f3f3f3f

 25 

 26 #define CLR( a, b )         memset( a, b, sizeof(a) )

 27 #define REP( i, a, b )      for( int i = (a); i < (b); ++i )

 28 #define FOR( i, a, b )      for( int i = (a); i <=(b); ++i )

 29 #define FOD( i, a, b )      for( int i = (a); i >=(b); --i )

 30 #define MID                 ( l + r ) >> 1

 31 #define lson                l, m, o << 1

 32 #define rson                m + 1, r, o << 1 | 1

 33 #define ls                  o << 1

 34 #define rs                  o << 1 | 1

 35 

 36 #define MAXN                1010101

 37 

 38 struct Node

 39 {

 40     int l, r;

 41     int co;

 42 }tree[MAXN << 2];

 43 int cnt, Hash[32], ans[32];

 44 

 45 

 46 void PushDown( int o )

 47 {

 48     if( tree[o].co )

 49     {

 50         tree[ls].co = tree[rs].co = tree[o].co;

 51         tree[o].co = 0;

 52     }

 53 }

 54 

 55 void Build( int l, int r, int o )

 56 {

 57     tree[o].l = l, tree[o].r = r, tree[o].co = 2;

 58     if( l == r )

 59     {

 60         return;

 61     }

 62     int m = MID;

 63     Build( lson );

 64     Build( rson );

 65 }

 66 

 67 void Update( int L, int R, int v, int o )

 68 {

 69     if( tree[o].l == L && tree[o].r == R )

 70     {

 71         tree[o].co = v;

 72         return;

 73     }

 74     PushDown( o );

 75     int m = ( tree[o].l + tree[o].r ) >> 1;

 76     if(R <= m)        Update( L, R, v, ls );

 77     else if(L >  m)    Update( L, R, v, rs );

 78     else

 79     {

 80         Update( L, m, v, ls );

 81         Update( m+1, R, v, rs );

 82     }

 83 }

 84 

 85 void Query ( int L , int R , int o )

 86 {

 87     if( tree[o].co )

 88     {

 89         if( Hash[ tree[o].co ] == 0 ) 

 90         {

 91             Hash[ tree[o].co ] = 1;

 92             ans[cnt++] = tree[o].co;

 93         }

 94         return;

 95     }

 96     int m = ( tree[o].l + tree[o].r ) >> 1;

 97     if( R <= m )        Query( L, R, ls );

 98     else if( L >  m )    Query( L, R, rs );

 99     else

100     {

101         Query( L, m, ls );

102         Query( m+1, R, rs );

103     }

104     

105 }

106 

107 

108 void Orz()

109 {

110     int N,M;

111     int l, r, co;

112     char ch;

113     while( ~scanf("%d%d",&N,&M) && (N+M) )

114     {

115         getchar();

116         CLR( ans, 0 );

117         Build(1,N,1);

118         while( M-- )

119         {

120             ch = getchar();

121             if( ch == 'P' )

122             {

123                 scanf( "%d %d %d", &l, &r, &co );

124                 Update( l, r, co, 1 );

125             }

126             else

127             {

128                 CLR( Hash, 0 );

129                 cnt = 0;

130                 scanf( "%d %d", &l, &r );

131                 Query( l, r, 1 );

132                 sort( ans, ans+cnt );

133                 int flag = 0;

134                 REP( i, 0, cnt )

135                 {

136                     if(flag)    printf( " %d", ans[i] );

137                     else

138                     {

139                         flag = 1;

140                         printf( "%d", ans[i] );

141                     }

142                 }

143                 puts("");

144             }

145             getchar();

146         }

147     }

148 }

149 

150 

151 int main()

152 {

153     #ifdef  BUG

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

155     #endif

156     Orz();

157     return 0;

158 }

代码君