hdoj 1015 Safecracker---盗窃贼

AOJ 怎么了 。。。还不好。。

English is very useful !深深为自己的英文感到惋惜。。。。。。

"The item is locked in a Klein safe behind a painting in the second-floor library. Klein safes are extremely rare; most of them, along with Klein and his factory, were destroyed in World War II. Fortunately old Brumbaugh from research knew Klein's secrets and wrote them down before he died. A Klein safe has two distinguishing features: a combination lock that uses letters instead of numbers, and an engraved quotation on the door. A Klein quotation always contains between five and twelve distinct uppercase letters, usually at the beginning of sentences, and mentions one or more numbers. Five of the uppercase letters form the combination that opens the safe. By combining the digits from all the numbers in the appropriate way you get a numeric target. (The details of constructing the target number are classified.) To find the combination you must select five letters v, w, x, y, and z that satisfy the following equation, where each letter is replaced by its ordinal position in the alphabet (A=1, B=2, ..., Z=26). The combination is then vwxyz. If there is more than one solution then the combination is the one that is lexicographically greatest, i.e., the one that would appear last in a dictionary."
"Develop a program to find Klein combinations in preparation for field deployment. Use standard test methodology as per departmental regulations. Input consists of one or more lines containing a positive integer target less than twelve million, a space, then at least five and at most twelve distinct uppercase letters. The last line will contain a target of zero and the letters END; this signals the end of the input. For each line output the Klein combination, break ties with lexicographic order, or 'no solution' if there is no correct combination. Use the exact format shown below."

v - w^2 + x^3 - y^4 + z^5 = target

Sample Input

1 ABCDEFGHIJKL11700519 ZAYEXIWOVU3072997 SOUGHT1234567 THEQUICKFROG0 END

 

 

Sample Output

LKEBAYOXUZGHOSTno solution

 

 英语看了半天 。。诶呀呀。。。。谷哥、度娘终于告诉我这道题的意思！

果断深搜 记得曾做过幂集 原理一样啊 ！

一次就Accepted了 。。。相当高兴。。。

今天加深了对栈保存数据的应用的印象 本来想用C++的sort 的，额。。。好像不起作用。。学了快速排序 其实也挺简单的。。只不过以前想的太多了。。。

记一下深搜的特点  退出条件 加 搜索 加设置相关变量 恢复相关变量 。。。

#include <iostream>#include <algorithm>#include <string.h>#include <stdlib.h>using namespace std;typedef struct Node{  char ch;  int num;}Node;int target;char str[27];Node a[27];int len;bool visited[27];char stack[6];int top=0;int flag=0;int cmp(const void *a,const void *b){Node *c=(Node *)a;Node *d=(Node *)b;return d->ch-c->ch;}int caculate(int dep,int n){  switch(dep)  {  case 0: return n;  case 1: return -n*n;  case 2: return n*n*n;  case 3: return -n*n*n*n;  case 4: return n*n*n*n*n;  }  return 0;}void print(){int i;for(i=0;i<top;i++){cout<<stack[i];}cout<<endl;}void dfs(int dep,int ans){  if(dep>5) return;  if(dep==5&&ans==target)  {  //cout<<"YES"<<endl;  flag=1;  print();  return;  }  int i;  for(i=0;i<len;i++)  {      if(!visited[i])  {                  visited[i]=true;stack[top++]=a[i].ch;                  ans+=caculate(dep,a[i].num);dfs(dep+1,ans);if(flag==1)return;visited[i]=false;top--;ans-=caculate(dep,a[i].num);  }  }}int main(){ while(cin>>target>>str,target!=0&&strcmp(str,"END")!=0) { len=strlen(str); int i; //将字符串转化为数字并保存到结点数组中 for(i=0;i<len;i++) {   a[i].ch=str[i];   a[i].num=str[i]-'A'+1; } qsort(a,len,sizeof(a[0]),cmp); memset(visited,false,27); dfs(0,0); if(flag==0) cout<<"no solution"<<endl; flag=0; top=0; } return 0;}