P6852

see you again

#include<bits/stdc++.h>
using namespace std;
int n,m,x,y,v,Lok[500010],Rok[500010],Lban[500010],Rban[500010],pre[500010],ans[500010];
bool findans;
set<int>st;
template <typename T>
inline void read(T &ans) {
	ans=0;
	char ch=getchar(),f=1;
	for(; ch<'0'||ch>'9'; ch=getchar())
		if(ch=='-')f=0;
	for(; ch>='0'&&ch<='9'; ch=getchar())
		ans=(((ans<<2)+ans)<<1)+(ch^'0');
	ans=f?ans:-ans;
}
void write(int x) {
	if(x>=10)write(x/10);
	putchar(x%10+'0');
}
int main() {
	read(n);
	read(m);
	for(int i=0; i<=n; i++)st.insert(i);
	for(int i=0; i<=n+1; i++)Lok[i]=0,Rok[i]=n,Lban[i]=n+1,Rban[i]=-1;
	for(int i=1; i<=m; i++) {
		read(x);
		read(y);
		read(v);
		if(v)Lok[v-1]=max(Lok[v-1],x),Rok[v-1]=min(Rok[v-1],y),Lban[v]=min(Lban[v],x),Rban[v]=max(Rban[v],y);
		else pre[x]++,pre[y+1]--;
	}
	for(int i=n; i>=0; i--)Lok[i]=max(Lok[i],Lok[i+1]),Rok[i]=min(Rok[i],Rok[i+1]);
	for(int i=0; i<=n; i++) {
		pre[i]+=pre[i-1];
		if(Lok[0]<=i&&i<=Rok[0]&&pre[i]==0) {
			ans[i]=0;
			st.erase(i);
			break;
		}
	}
	for(int i=1; i<=n; i++) {
		set<int>::iterator t=st.lower_bound(Lok[i]);
		if(t!=st.end()&&*t<=Rok[i]&&(Lban[i]>*t||*t>Rban[i]))ans[*t]=i,st.erase(t);
		else if(Rban[i]!=-1) {
			t=st.lower_bound(Rban[i]+1);
			if(t!=st.end()&&*t<=Rok[i])ans[*t]=i,st.erase(t);
		}
	}
	if(!st.empty()) {
		printf("-1\n");
		return 0;
	}
	for(int i=0; i<=n; i++)write(ans[i]),putchar(' ');
	printf("\n");
	return 0;
}