More than 2018 cattle off the summer school: Hash Function [Figure + segment tree optimization built topological sorting]

topic:

2018 cattle off more school fourth field: Hash Function

Meaning of the questions:

Known hash function hash (x) = x mod n, if the hash collision occurs, the hash (x) = hash (x + 1), until there is no conflict, are now given a hash table, output lexicographically minimum insertion sequence

analysis:

If x is not the hash (x) position, then the hash [x] to the position x where all numbers must first insert the ratio x, topological sorting run readily occur to FIG construction, but directly built FIG complexity N ^ 2, because the point of the range is the period of the construction side, considering the extent map of this segment to a point of the tree, each node of the tree line and his father even a one-way side (two sons had the ability to father ), was built to find the edge when the corresponding node can be built side note: It may be illegal interval, the interval is not filled with the prefix and determine the value of the minimum lexicographical priority leaf node just fine

Code:

#include <bits/stdc++.h>

using namespace std;
const int maxn = 2e6+255;
int tr[maxn<<2],a[maxn],sum[maxn],T,n;
struct edge{
    int to,nxt;
}e[maxn<<2];
int head[maxn<<2],cnt,pos[maxn<<2],val[maxn<<2],in[maxn<<2],vis[maxn<<2],num;
inline void add(int u,int v){
    e[++cnt].to = v;
    e[cnt].nxt = head[u];
    head[u] = cnt;
    in[v]++;
}
void build(int l,int r,int x){
    num++; val[x] = -1; vis[x] = 1;  //num记录总结点的个数，vis标记那些节点使用了
    if(l == r){
        pos[l] = x;
        val[x] = a[l];
        return ;
    }
    int mid = (l+r) >> 1;
    build(l,mid,x<<1);
    build(mid+1,r,x<<1|1);
    add(x<<1,x);add(x<<1|1,x);
}
void Updata(int l,int r,int L,int R,int x,int u){
    if(L > R) return;
    if(l > R || r < L) return ;
    if(l >= L && r <= R){
        add(x,u);
        return ;
    }
    int mid = (l+r) >> 1;
    Updata(l,mid,L,R,x<<1,u);
    Updata(mid+1,r,L,R,x<<1|1,u);
}
struct node{
    int x;
    friend bool operator <(node a,node b){
        return val[a.x] > val[b.x];
    }
};
vector<int> ans;

bool spafa(){
    priority_queue<node> q;
    int sum = 0;
    for(int i = 1;i <= (n<<2); ++i) if(!in[i]&&vis[i]) q.push(node{i});
    while(!q.empty()){
        node u = q.top();q.pop();
        sum++;
        if(~val[u.x]) ans.push_back(val[u.x]);
        for(int i = head[u.x]; i;i = e[i].nxt){
            int v = e[i].to;
            if(--in[v] == 0) q.push(node{v});
        }
    }
    return sum == num;
}
void init(int n){
    ans.clear();cnt = num = 0;
    for(int i = 0;i <= (n<<2); ++i) 
        head[i] = vis[i] = in[i] = 0;
}
int main(){
    scanf("%d",&T);
    while(T--){
        scanf("%d",&n);
        init(n);
        for(int i = 1;i <= n; ++i) scanf("%d",a+i);
        for(int i = 1;i <= n; ++i){
            sum[i] = sum[i-1];
            if(~a[i]) sum[i]++;
        }
        build(1,n,1); bool flag = true;
        for(int i = 1;i <= n && flag; ++i){
            if(~a[i]){
                int tep = a[i] % n + 1;
                if(i > tep) {
                    Updata(1,n,tep,i-1,1,pos[i]);
                    if(sum[i-1]-sum[tep-1] != i-tep) flag = false;
                }
                else if(i < tep){
                    Updata(1,n,tep,n,1,pos[i]);
                    if(sum[n]-sum[tep-1] != n-tep+1) flag = false;
                    Updata(1,n,1,i-1,1,pos[i]);
                    if(sum[i-1] != i-1) flag = false;
                }
            }
        }
        if(flag&&spafa()){
            for(int i = 0;i < (int)ans.size(); ++i) printf("%d ", ans[i]);
            putchar('\n');
        }
        else puts("-1");
    }
    return 0;
}