POJ2777

来源：互联网发布：画网络计划图的步骤编辑：程序博客网时间：2024/04/27 17:36

摘要：颜色覆盖，典型的线段树应用

#include <iostream>
#include <stdio.h>
#include <string.h>
using namespace std;

typedef struct Node{
   int left;
   int right;
   int color;
   Node * left_child;
   Node * right_child;
   void Insert(int, int, int);
   void Calculate(int, int);
   void Construct(int, int);
}Node;

const int size = 100000;
Node sTree[size * 6];
Node *root = &sTree[0];
int len = 1;
int result[size+1] = {0};
int cnt = 0;
bool hash_table[31] = {0};

void Node::Construct(int l, int r)
{
   left = l;
   right = r;
   color = 1;
   if(l == r){
       left_child = right_child = NULL;
       return;
   }

   left_child = &sTree[len++];
   right_child = &sTree[len++];

   int mid = (l + r) >> 1;
   left_child->Construct(l, mid);
   right_child->Construct(mid+1, r);
}

void Node::Insert(int l, int r, int c)
{
   if(color == c){
       return;
   }
   if(left==l && right==r){
       color = c;
       return;
   }
   if( color != -1){
       left_child->color = color;
       right_child->color = color;
   }
   color = -1;

   int mid = (left + right) >> 1;
   if(l > mid){
       right_child->Insert(l, r, c);
       return;
   }
   if(r <= mid){
       left_child->Insert(l, r, c);
       return;
   }
   left_child->Insert(l, mid, c);
   right_child->Insert(mid+1, r, c);
}

void Node::Calculate(int l, int r)
{
   if(color != -1){
       if( !hash_table[color] ){
           hash_table[color] = true;
           cnt++;
       }
       return;
   }

   int mid = (left + right) >> 1;

   if( l > mid ){
       right_child->Calculate(l, r);
       return;
   }
   if( r <= mid ){
       left_child->Calculate(l, r);
       return;
   }

   left_child->Calculate(l, mid);
   right_child->Calculate(mid+1, r);
}

int main()
{
   int L, T, N;
   scanf("%d%d%d", &L, &T, &N);
   len = 1;
   root->Construct(1, L);
   getchar();
   for(int i=1; i<=N; i++){
       int first, second, color;
       char op;
       op = getchar();
       scanf("%d%d", &first , &second);
       if( op == 'C' ){
           scanf("%d", &color);
           int left = first<second ? first : second;
           int right = first + second - left;
           root->Insert(left, right, color);
       }else{
           int left = first<second ? first : second;
           int right = first + second - left;
           memset(hash_table, 0, sizeof(hash_table));
           cnt = 0;
           root->Calculate(left, right);
           printf("%d/n", cnt);
       }
       getchar();
   }

   return 0;
}