UVa 12299 - RMQ with Shifts

题目链接：

线段树，点修改。

  1 #include <cstdio>
  2 #include <cctype>
  3 #define lson l, m, rt << 1
  4 #define rson m + 1, r, ( rt << 1 ) | 1
  5 
  6 const int MAXN = 100010;
  7 const int INF = 2147483645;
  8 
  9 int tree[ MAXN << 2 ];
 10 
 11 int min( int a, int b )
 12 {
 13     return a < b ? a : b;
 14 }
 15 
 16 void PushUP( int rt )
 17 {
 18     tree[rt] = min( tree[rt << 1] , tree[ rt << 1 | 1 ] );
 19     return;
 20 }
 21 
 22 void build( int l, int r, int rt )
 23 {
 24     if ( l == r )
 25     {
 26         scanf( "%d", &tree[rt] );
 27         return;
 28     }
 29     int m = ( l + r ) >> 1;
 30     build(lson);
 31     build(rson);
 32     PushUP(rt);
 33 }
 34 
 35 void update( int p, int e, int l, int r, int rt )
 36 {
 37     if ( l == r )
 38     {
 39         tree[rt] = e;
 40         return;
 41     }
 42     int m = ( l + r ) >> 1;
 43     if ( p <= m ) update( p, e, lson );
 44     else update( p, e, rson );
 45     PushUP(rt);
 46     return;
 47 }
 48 
 49 void GetNum( int p, int &e, int l, int r, int rt )
 50 {
 51     if ( l == r )
 52     {
 53         e = tree[rt];
 54         return;
 55     }
 56     int m = ( l + r ) >> 1;
 57     if ( p <= m ) GetNum( p, e, lson );
 58     else GetNum( p, e, rson );
 59     return;
 60 }
 61 
 62 int Query( int L, int R, int l, int r, int rt )
 63 {
 64     if ( L <= l && R >= r )
 65        return tree[rt];
 66 
 67     int ret = INF;
 68     int m = ( l + r ) >> 1;
 69     if ( L <= m ) ret = min( ret, Query( L, R, lson ) );
 70     if ( R > m ) ret = min( ret, Query( L, R, rson ) );
 71     return ret;
 72 }
 73 
 74 int main()
 75 {
 76     int n, Q;
 77     char order[50];
 78     int addr[50], number[50];
 79     while ( ~scanf( "%d%d", &n, &Q ) )
 80     {
 81         build( 1, n, 1 );
 82         while ( Q-- )
 83         {
 84             scanf( "%s", order );
 85             if ( order[0] == 'q' )
 86             {
 87                 int x, y;
 88                 sscanf( order, "query(%d,%d)", &x, &y );
 89 //                printf("##%d %d\n", x, y);
 90                 printf( "%d\n", Query( x, y, 1, n, 1 ) );
 91             }
 92             else
 93             {
 94                 int cnt = 0;
 95                 for ( int i = 0; order[i]; )
 96                 {
 97                     if ( isdigit( order[i] ) )
 98                     {
 99                         int sum = 0;
100                         while ( isdigit( order[i] ) )
101                             sum = sum * 10 + order[i++] - '0';
102                         addr[cnt++] = sum;
103                     }
104                     else ++i;
105                 }
106 
107                 for ( int i = 0; i < cnt; ++i )
108                 {
109                //     printf( "=%d ", addr[i] );
110                     GetNum( addr[i], number[i], 1, n, 1 );
111                //     printf( "@%d\n", number[i] );
112                 }
113                 for ( int i = 0; i < cnt; ++i )
114                 {
115                     if ( i == cnt - 1 ) update( addr[i], number[0], 1, n, 1 );
116                     else update( addr[i], number[i + 1], 1, n, 1 );
117                 }
118             }
119         }
120     }
121     return 0;
122 }

 

posted @ 2012-12-04 20:52  冰鸮  阅读(265)  评论(0)  编辑  收藏  举报