正题

题目：
http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=610

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题意

有一条长m的线，有n条长度和颜色不同的线段，每个颜色可以看到的段数。

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解题思路

标记颜色-2表示有多种颜色，然后用color表示上次的颜色以去重。

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代码

#include<cstdio>
#include<cstring>
using namespace std;
struct xjq{int l,r,cover;
}tree[30001];
int flag[30001];
int n,ll,rr,w,s,cl,color;
void build(int x,int a,int b)//建树
{tree[x].l=a;tree[x].r=b;tree[x].cover=-1;if (b-a==1) return;else{int m=(a+b)/2;build(x*2,a,m);build(x*2+1,m,b);}
}
void inster(int x,int a,int b,int c)//插入
{if (tree[x].cover==c) return;if (tree[x].l==a && tree[x].r==b){tree[x].cover=c;return;}if (tree[x].cover>=-1){tree[x*2].cover=tree[x].cover;tree[x*2+1].cover=tree[x].cover;tree[x].cover=-2;}int m=tree[x*2].r;if (b<=m) inster(x*2,a,b,c);else if (a>=m) inster(x*2+1,a,b,c);else{inster(x*2,a,m,c);inster(x*2+1,m,b,c);}return;
}
void find(int x)//查询
{if (tree[x].cover>=-1){if (tree[x].cover!=-1 && tree[x].cover!=color)flag[tree[x].cover]++;//统计color=tree[x].cover;//标记return;}if (tree[x].r-tree[x].l==1) return;else{find(x*2);find(x*2+1);}
}
int main()
{while (scanf("%d",&n)!=EOF){memset(tree,0,sizeof(tree));memset(flag,0,sizeof(flag));for (int i=1;i<=8000;i++) tree[i].cover=-1;build(1,0,8000);for (int i=1;i<=n;i++){scanf("%d%d%d",&ll,&rr,&cl);inster(1,ll,rr,cl);}s=0;color=-3;find(1);for (int i=0;i<=30000;i++)if (flag[i])printf("%d %d\n",i,flag[i]);//输出printf("\n");//printf("%d\n",s);}
}