题意及思路：

代码：

#include 
     
      #define LL long long#define db doubleusing namespace std;const int maxn = 500010;stack
      
       
         >s;vector
        
          G[maxn];int a[maxn], ans[maxn], tot, n;void topsort(void) {	queue
         
           q;	q.push(n + 1);	while(!q.empty()) {		int x = q.front();		q.pop();		for (int i = 0; i < G[x].size(); i++) {			int y = G[x][i];			ans[y] = tot--;			q.push(y);		}	}}int main() {	int T;	scanf("%d", &T);	while(T--) {		scanf("%d", &n);		tot = n;		while(!s.empty())s.pop();		for (int i = 1; i <= n + 1; i++) G[i].clear();		bool flag = 0;		for (int i = 1; i <= n; i++) {			scanf("%d", &a[i]);			if(a[i] == -1) a[i] = i + 1;			while(!s.empty() && s.top().second <= i) s.pop();			if(!s.empty() && a[i] > s.top().second) {				flag = 1;			} else {				s.push(make_pair(i, a[i]));				G[a[i]].push_back(i);			}		}		if(flag) {			printf("-1\n");		}		else {			topsort();			for (int i = 1; i <= n; i++) printf("%d ", ans[i]);			printf("\n");		}	}	}