uestc的方老师与素数是不是就是根据这个题改的。。
感觉好像代码都完全一样。。
1 #include<iostream> 2 #include<cstdio> 3 #include<cstdlib> 4 #include<cstring> 5 #include<string> 6 #include<queue> 7 #include<algorithm> 8 #include<map> 9 #include<iomanip> 10 #include<climits> 11 #include<string.h> 12 #include<numeric> 13 #include<cmath> 14 #include<stdlib.h> 15 #include<vector> 16 #include<stack> 17 #include<set> 18 #define INF 1e7 19 #define MAXN 100010 20 #define maxn 1000010 21 #define Mod 1000007 22 #define N 1299800 23 using namespace std; 24 typedef long long LL; 25 26 int prime[N]; 27 int vis[N]; 28 void run() 29 { 30 int k = 1; 31 for (LL i = 2; i <= N; ++i) 32 if (!vis[i]) { 33 prime[k++] = i; 34 for (LL j = i*i; j < N; j += i) 35 vis[j] = 1; 36 } 37 /*for (int i = 1; i < 1300; ++i) 38 cout << prime[i] << " "; 39 cout << endl;*/ 40 } 41 42 int n, m; 43 int T; 44 int used[11000]; 45 46 int bfs() 47 { 48 queue<int> q; 49 int step = 0; 50 q.push(n); 51 used[n] = 1; 52 q.push(-1); 53 while (!q.empty()) { 54 int now = q.front(); 55 if (now == -1) { 56 q.pop(); 57 if (q.empty()) return -1; 58 step++; 59 q.push(-1); continue; 60 }q.pop(); 61 if (now == m) return step; 62 for (int i = 0; i < 4; ++i) { 63 if (i == 0) { 64 for (int j = 1; j <= 9; ++j) { 65 if (now / 1000 == j) continue; 66 int next = j * 1000 + now % 1000; 67 if (!vis[next] && !used[next]) { 68 q.push(next); 69 used[next] = 1; 70 } 71 } 72 } 73 else if (i == 1) { 74 for (int j = 0; j <= 9; ++j) { 75 if ((now / 100) % 10 == j) continue; 76 int next = j * 100 + now % 100 + (now / 1000) * 1000; 77 if (!vis[next] && !used[next]) { 78 q.push(next); 79 used[next] = 1; 80 } 81 } 82 } 83 else if (i == 2) { 84 for (int j = 0; j <= 9; ++j) { 85 if ((now / 10) % 10 == j) continue; 86 int next = j * 10 + now % 10 + (now / 100) * 100; 87 if (!vis[next] && !used[next]) { 88 q.push(next); 89 used[next] = 1; 90 } 91 } 92 } 93 else if (i == 3) { 94 for (int j = 0; j <= 9; ++j) { 95 if (now % 10 == j) continue; 96 int next = j + (now / 10) * 10; 97 if (!vis[next] && !used[next]) { 98 q.push(next); 99 used[next] = 1; 100 } 101 } 102 } 103 } 104 } 105 return -1; 106 } 107 108 109 void process() 110 { 111 memset(used, 0, sizeof(used)); 112 scanf("%d%d", &n, &m); 113 int ans = bfs(); 114 if (ans == -1) puts("Impossible"); 115 else printf("%d ",ans); 116 } 117 118 int main() 119 { 120 run(); 121 scanf("%d", &T); 122 while (T--) 123 process(); 124 return 0; 125 }