zoj 1610 Count the Colors

#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <cstring>
#include <string>
#include <algorithm>
#include <queue>
#include <stack>
#include <climits>
#define L(x) (x << 1)
#define R(x) (x << 1 | 1)

using namespace std;

const int MAX = 8010;
struct Tnode{ int col; int l,r;};
Tnode node[MAX*4];
int col[MAX],len[MAX];;
void init()
{
memset(node,0,sizeof(node));
memset(col,-1,sizeof(col));
}
void Build(int t,int l,int r)
{
node[t].l = l;
node[t].r = r;
node[t].col = -1;
if( l == r - 1 ) return ;
int mid = ( l + r ) >> 1;
Build(L(t), l, mid);
Build(R(t), mid, r);
}

void Updata(int t,int l,int r,int col)
{
if( node[t].l >= l && node[t].r <= r )
{
node[t].col = col;
return ;
}
if( node[t].col == col ) return ;
if( node[t].col >= 0 )
{
node[R(t)].col = node[t].col;
node[L(t)].col = node[t].col;
node[t].col = -1;
}
int mid = (node[t].l + node[t].r) >> 1;
if( l >= mid )
Updata(R(t),l,r,col);
else
if( r <= mid )
Updata(L(t),l,r,col);
else
{
Updata(L(t),l,mid,col);
Updata(R(t),mid,r,col);
}
}
void Compute(int t,int l,int r)
{
if( node[t].col >= 0 )
{
for(int i=l; i<r; i++)
col[i] = node[t].col;
return ;
}
if( node[t].l == node[t].r - 1 ) return ;// 如果父亲节点已经是这种颜色了，就没必要再染色了
int mid = (node[t].l + node[t].r) >> 1;
if( l >= mid )
Compute(R(t),l,r);
else
if( r <= mid )
Compute(L(t),l,r);
else
{
Compute(L(t),l,mid);
Compute(R(t),mid,r);
}
}

int main()
{
int n,x,y,color;

while( ~scanf("%d",&n) )
{
init();
Build(1,0,8000);
while( n-- )
{
scanf("%d%d%d",&x,&y,&color);
Updata(1,x,y,color);
}
Compute(1,0,8000);
memset(len,0,sizeof(len));
for(int i=0; i<MAX; i++)
if( col[i+1] != col[i] && col[i] != -1 )
len[col[i]]++;
for(int i=0; i<MAX; i++)
if( len[i] )
printf("%d %d\n",i,len[i]);
printf("\n");
}

return 0;
}