codeforces 224B Undoubtedly Lucky Numbers
题目链接:http://codeforces.com/problemset/problem/244/B
解题思路:DFS 搜索
1 /************************************************************************** 2 user_id: SCNU20102200088 3 problem_id: codeforces 244B 4 problem_name: Undoubtedly Lucky Numbers 5 **************************************************************************/ 6 7 #include <algorithm> 8 #include <iostream> 9 #include <iterator> 10 #include <iomanip> 11 #include <sstream> 12 #include <fstream> 13 #include <cstring> 14 #include <cstdlib> 15 #include <climits> 16 #include <bitset> 17 #include <string> 18 #include <vector> 19 #include <cstdio> 20 #include <cctype> 21 #include <ctime> 22 #include <cmath> 23 #include <queue> 24 #include <stack> 25 #include <list> 26 #include <set> 27 #include <map> 28 using namespace std; 29 30 //线段树 31 #define lson l,m,rt<<1 32 #define rson m+1,r,rt<<1|1 33 34 //手工扩展栈 35 #pragma comment(linker,"/STACK:102400000,102400000") 36 37 const double EPS=1e-9; 38 const double PI=acos(-1.0); 39 const double E=2.7182818284590452353602874713526; //自然对数底数 40 const double R=0.5772156649015328606065120900824; //欧拉常数:(1+1/2+...+1/n)-ln(n) 41 42 const int x4[]={-1,0,1,0}; 43 const int y4[]={0,1,0,-1}; 44 const int x8[]={-1,-1,0,1,1,1,0,-1}; 45 const int y8[]={0,1,1,1,0,-1,-1,-1}; 46 47 typedef long long LL; 48 49 typedef int T; 50 T max(T a,T b){ return a>b? a:b; } 51 T min(T a,T b){ return a<b? a:b; } 52 T gcd(T a,T b){ return b==0? a:gcd(b,a%b); } 53 T lcm(T a,T b){ return a/gcd(a,b)*b; } 54 55 /////////////////////////////////////////////////////////////////////////// 56 //Add Code: 57 set<LL> s; 58 59 void DFS(int n,int i,int j,LL res,int cnt){ 60 if(res>n || (res==0 && cnt>0)) return ; 61 if(res>0) s.insert(res); 62 DFS(n,i,j,10*res+i,cnt+1); 63 DFS(n,i,j,10*res+j,cnt+1); 64 } 65 /////////////////////////////////////////////////////////////////////////// 66 67 int main(){ 68 std::ios::sync_with_stdio(false); 69 //freopen("in.txt","r",stdin); 70 //freopen("out.txt","w",stdout); 71 /////////////////////////////////////////////////////////////////////// 72 //Add Code: 73 int n,i,j; 74 scanf("%d",&n); 75 for(i=0;i<9;i++){ 76 for(j=i+1;j<=9;j++) DFS(n,i,j,0,0); 77 } 78 printf("%d\n",s.size()); 79 /////////////////////////////////////////////////////////////////////// 80 return 0; 81 } 82 83 /************************************************************************** 84 Testcase: 85 Input: 86 10 87 123 88 Output: 89 10 90 113 91 **************************************************************************/
posted on 2013-09-23 21:18 SCNU20102200088 阅读(428) 评论(0) 编辑 收藏 举报