PKU POJ 2777 Count Color

线段树入门题

#include < iostream >
#define  N 1000000
using   namespace  std;
struct  line
{    int  left,right;
     int  col;
}a[N];
int  n,t,o;
bool  c[ 31 ] = { 0 };
char  s;
int  aa,bb,cc;
void  build( int  i, int  j, int  v)
{   
    a[v].left = i;
    a[v].right = j;
    a[v].col = 1 ;
     if (a[v].left < a[v].right)
    {     int  mid = (i + j) >> 1 ;
         build(i,mid, 2 * v);
         build(mid + 1 ,j, 2 * v + 1 );
    }
}
void  insert( int  i, int  j, int  v, int  q)
{    if (a[v].left == i && a[v].right == j)
    {   a[v].col = q;
         return  ;
    }
     else   if (a[v].left < a[v].right)
    {    int  mid = (a[v].left + a[v].right) >> 1 ;
         if (a[v].col >= 1 )
        {   a[ 2 * v].col = a[v].col;
            a[ 2 * v + 1 ].col = a[v].col;
            a[v].col =- 1 ;
        }
         if (j <= mid)
        {   insert(i,j, 2 * v,q);
        }
         else   if (i > mid)
        {   insert(i,j, 2 * v + 1 ,q);
        }
         else  
        {  insert(i,mid, 2 * v,q);
           insert(mid + 1 ,j, 2 * v + 1 ,q);
        }
    }
}
void  check( int  s, int  t, int  v)
{     if (a[v].col > 0 )
     {   c[a[v].col] = 1 ;
          return  ;
     }
      else   if (a[v].col ==- 1 && a[v].left < a[v].right)
     {    int  mid = (a[v].left + a[v].right) >> 1 ;
          if (t <= mid)
         {   check(s,t, 2 * v);
         }
          else   if (s > mid)
         {   check(s,t, 2 * v + 1 );
         }
          else
         {   check(s,mid, 2 * v);
             check(mid + 1 ,t, 2 * v + 1 );
         }
     }
}
int  cnt()
{    int  i;
     int  s = 0 ;
     for (i = 1 ;i <= 30 ;i ++ )
    {   if (c[i])
         s ++ ;
    }
     return  s;
}
int  main()
{   
    scanf( " %d%d%d " , & n, & t, & o);
    getchar();
    build( 1 ,n, 1 );
     while (o -- )
    {  scanf( " %c " , & s);
       getchar();
        if (s == ' C ' )
       {  scanf( " %d%d%d " , & aa, & bb, & cc);
          getchar();
           if (aa <= bb)
             insert(aa,bb, 1 ,cc);
           else  insert(bb,aa, 1 ,cc);
       }
        else  
       {   
           scanf( " %d%d " , & aa, & bb);
           getchar();
           memset(c, 0 , sizeof (c));
            if (aa <= bb)
               check(aa,bb, 1 );
            else  check(bb,aa, 1 );
           printf( " %d\n " ,cnt());
       }
    }
    system( " pause " );
     return   0 ;
}