POJ 3277 City Horizon

#include <set>
#include <map>
#include <queue>
//#include <math.h>
#include <vector>
#include <string>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <iostream>
#include <algorithm>

#define eps 1e-8
#define pi acos(-1.0)
#define inf 107374182
#define inf64 1152921504606846976
#define lc l,m,tr<<1
#define rc m + 1,r,tr<<1|1
#define iabs(x)  ((x) > 0 ? (x) : -(x))
#define clear1(A, X, SIZE) memset(A, X, sizeof(A[0]) * (SIZE))
#define clearall(A, X) memset(A, X, sizeof(A))
#define memcopy1(A , X, SIZE) memcpy(A , X ,sizeof(X[0])*(SIZE))
#define memcopyall(A, X) memcpy(A , X ,sizeof(X))
#define max( x, y )  ( ((x) > (y)) ? (x) : (y) )
#define min( x, y )  ( ((x) < (y)) ? (x) : (y) )

using namespace std;

struct node2
{
int num;
long long y,l,r;
} edge[80005];

long long tempx[80005],binx[80005];
long long x1,x2,y1,y2,ans;
int cntx,n;

bool cmp(node2 a,node2 b)
{
return a.y<b.y;
}

int binnum(long long num)
{
int ll=0,m,rr=cntx-1;
while(rr>ll)
{
m=(ll+rr)>>1;
if(binx[m]==num)return m;
else if(binx[m]<num)ll=m+1;
else rr=m-1;
}
return ll;
}

struct node1
{
long long disnow;
int cnt;
} node[80005<<2];

inline void PushUp(int l,int r,int tr)
{
if(node.cnt)node.disnow=binx[r+1]-binx[l];
else if(l==r)node.disnow=0;
else node.disnow=node[tr<<1].disnow+node[tr<<1|1].disnow;
}

void update(int L,int R,int num,int l,int r,int tr)
{
if(L<=l&&r<=R)
{
node.cnt+=num;
PushUp(l,r,tr);
return ;
}
int m=(l+r)>>1;
if(L<=m)update(L,R,num,l,m,tr<<1);
if(m<R)update(L,R,num,m+1,r,tr<<1|1);
PushUp(l,r,tr);
}
int main()
{
int case1=1;
while(scanf("%d",&n)!=EOF)
{
for(int i=0; i<n; i++)
{
scanf("%d%d%d",&x1,&x2,&y2);
tempx[2*i]=x1;
tempx[2*i+1]=x2;
edge[2*i].l=x1;
edge[2*i].r=x2;
edge[2*i+1]=edge[2*i];
edge[2*i].y=0;
edge[2*i+1].y=y2;
edge[2*i].num=1;
edge[2*i+1].num=-1;
}
sort(tempx,tempx+2*n);
binx[0]=tempx[0];
cntx=1;
for(int i=1; i<2*n; i++)
{
if(tempx[i]!=binx[cntx-1])
{
binx[cntx++]=tempx[i];
}
}
sort(edge,edge+2*n,cmp);
clearall(node,0);
ans=0;
x1=binnum(edge[0].l);
x2=binnum(edge[0].r);
x2--;
update(x1,x2,edge[0].num,0,cntx-2,1);
y1=edge[0].y;
for(int i=1; i<2*n; i++)
{
ans+=node[1].disnow*(edge[i].y-y1);
y1=edge[i].y;
x1=binnum(edge[i].l);
x2=binnum(edge[i].r);
x2--;
update(x1,x2,edge[i].num,0,cntx-2,1);
}
printf("%lld\n",ans);
}
return 0;
}