CF1209F Koala and Notebook

 1 #include <bits/stdc++.h>
 2  
 3 using namespace std;
 4  
 5 const int N = 1e6 + 10;
 6 const int mod = 1e9 + 7;
 7 inline int read()
 8 {
 9     char ch = getchar();int x = 0, f = 1;
10     while(ch < ‘0‘ || ch > ‘9‘) {if(ch == ‘-‘) f = -1; ch = getchar();}
11     while(ch >= ‘0‘ && ch <= ‘9‘) {x = (x << 1) + (x << 3) - ‘0‘ + ch; ch = getchar();}
12     return x * f;
13 }
14  
15 int n, m, cnt;
16 vector<int>g[N][10], q[N];
17 int c[N];
18 int st[N];
19 int ans[N];
20 int vis[N];
21  
22 void add(int x, int y, int z)
23 {
24     int res = 0;
25     while(z) c[++ res] = z % 10, z /= 10;
26     int last = x, now;
27     for (int i = res; i >= 1; i --)
28     {
29         if(i != 1) now = ++ cnt;
30         else now = y;
31         g[last][c[i]].push_back(now);
32         last = now;
33     }
34     last = y;
35     for (int i = res; i >= 1; i --)
36     {
37         if(i != 1) now = ++ cnt;
38         else now = x;
39         g[last][c[i]].push_back(now);
40         last = now;
41     }
42 }
43  
44  
45 int main()
46 {
47     n = read(), m = read();
48     cnt = n;
49     for (int i = 1; i <= m; i ++)
50     {
51         int x = read(), y = read();
52         add(x, y, i);
53     }
54     int t = 1;
55     q[1].push_back(1);
56     st[1] = 1;
57     for (int i = 1; i <= t; i ++)
58     {
59         for (int j = 0; j <= 9; j ++)
60         {
61             bool flag =false;
62             for (int k = 0; k < q[i].size(); k ++)
63             {
64                 int tt = q[i][k];
65  
66                 for (auto w : g[tt][j])
67                 {
68                     if(!st[w])
69                     {
70                         ans[w] = (1ll * ans[tt] * 10% mod + j) % mod;
71                         flag = true;
72                         st[w] = 1;
73                         q[t + 1].push_back(w);
74                     }
75                 }
76             }
77             if(flag) ++ t;
78         }
79     }
80     for (int i = 2; i <= n; i ++)
81     {
82         printf("%d\n", ans[i]);
83     }
84 }