POJ1248/HDOJ1015——Safecracker

水题就要任性地用很水的方法来解~

大体题意：给定一个target、一个由大写字母组成的字符串，从中任选5个，设为v,w,x,y,z,求满足v-w^2+x^3-y^4+z^5=target的5个字符，可能多解，输出字典序最大解，无解输出“no solution”

Problem Description：

=== Op tech briefing, 2002/11/02 06:42 CST ==="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."v - w^2 + x^3 - y^4 + z^5 = target quot;For example, given target 1 and letter set ABCDEFGHIJKL, one possible solution is FIECB, since 6 - 9^2 + 5^3 - 3^4 + 2^5 = 1. There are actually several solutions in this case, and the combination turns out to be LKEBA. Klein thought it was safe to encode the combination within the engraving, because it could take months of effort to try all the possibilities even if you knew the secret. But of course computers didn't exist then."

=== Op tech directive, computer division, 2002/11/02 12:30 CST === "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." 

        Sample Input

1 ABCDEFGHIJKL

11700519 ZAYEXIWOVU

3072997 SOUGHT

1234567 THEQUICKFROG

0 END

Sample Output

LKEBA

YOXUZ

GHOST

no solution 

A的码：

#include<iostream>#include<cstring>#include<algorithm>#define cti(c) c-'A'    //char to int using namespace std;//君莫笑~君莫笑~~方法就是那么水！//这个表是另用程序跑出来打印在txt里复制过来的结果//其实直接把v - w^2 + x^3 - y^4 + z^5放到循环里照样Aint a[26][5]={{1,1,1,1,1},{2,4,8,16,32},{3,9,27,81,243},{4,16,64,256,1024},{5,25,125,625,3125},{6,36,216,1296,7776},{7,49,343,2401,16807},{8,64,512,4096,32768},{9,81,729,6561,59049},{10,100,1000,10000,100000},{11,121,1331,14641,161051},{12,144,1728,20736,248832},{13,169,2197,28561,371293},{14,196,2744,38416,537824},{15,225,3375,50625,759375},{16,256,4096,65536,1048576},{17,289,4913,83521,1419857},{18,324,5832,104976,1889568},{19,361,6859,130321,2476099},{20,400,8000,160000,3200000},{21,441,9261,194481,4084101},{22,484,10648,234256,5153632},{23,529,12167,279841,6436343},{24,576,13824,331776,7962624},{25,625,15625,390625,9765625},{26,676,17576,456976,11881376},};int main(){int t,i,j,k,l,m,sum,w;char u[30],s[6];   //u输入的字符串  s存放结果s[5]=0;    while(cin>>t>>u&&(t!=0||strcmp(u,"END")!=0)){        int f = 0;   //判断无解标志        w=strlen(u);        sort(u,u+w);  //对字符串排序，方便取字典序最大解        w--;        for(i=w;i>=0;i--)   //暴力循环，还好数据量小{            for(j=w;j>=0;j--)  //每重循环都是对字符串从后向前取字符来找最大解{                for(k=w;k>=0;k--){                    for(l=w;l>=0;l--){                        for(m=w;m>=0;m--){                            if(i!=j&&i!=k&&i!=l&&i!=m&&j!=k&&j!=l&&j!=m&&k!=l&&k!=m&&l!=m) //去重 {//sum=v - w^2 + x^3 - y^4 + z^5                                sum=a[cti(u[i])][0]-a[cti(u[j])][1]+a[cti(u[k])][2]-a[cti(u[l])][3]+a[cti(u[m])][4];                                if(sum==t){                                    f=1;                                    s[0]=u[i];                                    s[1]=u[j];                                    s[2]=u[k];                                    s[3]=u[l];                                    s[4]=u[m];                                    cout<<s<<endl;                                    goto END;                                 }                            }                        }                    }                }            }        }        END:;        if(!f)cout<<"no solution"<<endl;    }    return 0;}