poj 3126 Prime Path

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\n",ans);
116 }
117 
118 int main()
119 {
120     run();
121     scanf("%d", &T);
122     while (T--)
123         process();
124     return 0;
125 }

 

posted @ 2015-03-26 18:39  UsedRose  阅读(104)  评论(0)  编辑  收藏  举报