学步园

  题目搞懂了，就是优化啊，在 test11 TLE两次，看人家的解法，优化的很精巧

#include<stdio.h>
#include<stdlib.h>
using namespace std;
#define MN 300005
int ans[MN],p[MN];

int getl(int x)
{
	int i = x,j;
	while(x != p[x]){
		x = p[x];
	}
	while(i != p[i]){
		j = p[i];
		p[i] = x;
		i = j;
	}
	return x;
}

int main(void)
{
	int m,n,l,r,x;
	scanf("%d %d",&n,&m);
	for(int i=1;i<=n+1;i++)
	    p[i] = i;
	for(int i=1;i<=m;i++)
	{
		scanf("%d %d %d",&l,&r,&x);
		int j = getl(l);
		while(j <= r)
		{
			if(j != x )
			{
				ans[j] = x;
				p[j] = j+1;
			}
			j = j + 1;
			j = getl(j);
		}
	}
	for(int i=1;i<=n;i++)	
	     printf("%d ",ans[i]);
	//system("pause");
	return 0;
}