pat 1136 A Delayed Palindrome（20 分）

1136 A Delayed Palindrome（20 分）

Consider a positive integer N written in standard notation with k+1 digits ai as ak⋯a1a0 with 0≤ai<10 for all i and ak>0. Then N is palindromic if and only if ai=ak−i for all i. Zero is written 0 and is also palindromic by definition.

Non-palindromic numbers can be paired with palindromic ones via a series of operations. First, the non-palindromic number is reversed and the result is added to the original number. If the result is not a palindromic number, this is repeated until it gives a palindromic number. Such number is called a delayed palindrome. (Quoted from https://en.wikipedia.org/wiki/Palindromic_number )

Given any positive integer, you are supposed to find its paired palindromic number.

Input Specification:

Each input file contains one test case which gives a positive integer no more than 1000 digits.

Output Specification:

For each test case, print line by line the process of finding the palindromic number. The format of each line is the following:

A + B = C

where A is the original number, B is the reversed A, and C is their sum. A starts being the input number, and this process ends until C becomes a palindromic number -- in this case we print in the last line C is a palindromic number.; or if a palindromic number cannot be found in 10 iterations, print Not found in 10 iterations. instead.

Sample Input 1:

Sample Output 1:

97152 + 25179 = 122331

122331 + 133221 = 255552

255552 is a palindromic number.

Sample Input 2:

Sample Output 2:

196 + 691 = 887

887 + 788 = 1675

1675 + 5761 = 7436

7436 + 6347 = 13783

13783 + 38731 = 52514

52514 + 41525 = 94039

94039 + 93049 = 187088

187088 + 880781 = 1067869

1067869 + 9687601 = 10755470

10755470 + 07455701 = 18211171

Not found in 10 iterations.

 #include <map>

 #include <set>

 #include <queue>

 #include <cmath>

 #include <stack>

 #include <vector>

 #include <string>

 #include <cstdio>

 #include <cstring>

 #include <climits>

 #include <iostream>

 #include <algorithm>

 #define wzf ((1 + sqrt(5.0)) / 2.0)

 #define INF 0x3f3f3f3f

 #define LL long long

 using namespace std;

 const int MAXN = 2e3 + ;

 char A[MAXN], B[MAXN], C[MAXN];

 void calcB()

 {

     int len = strlen(A), a = len - , b = ;

         for (a ,b ; b < len; ++ b, -- a)

             B[b] = A[a];

 }

 void calcC()

 {

     int len1 = strlen(A), len = len1, b = ;

     int temp[MAXN];

     for (int i = , j = len1 - ; i < len; ++ i, -- j)

     {

         if (j != -) b += int(A[j] - '') + int(B[j] - '');

         temp[i] = b % ;

         b /= ;

         if (i == len -  && b > ) ++ len;

     }

     for (int i = , j = len - ; i < len; ++ i, -- j)

         C[i] = char ('' + temp[j]);

 }

 int main()

 {

     scanf("%s", &A);

     int len = strlen(A), a = len - , b = ;

         for (a ,b ; b < len; ++ b, -- a)

             B[b] = A[a];

     for (int i = ; ; ++ i)

     {

         if (i == )

         {

             printf("Not found in 10 iterations.\n");

             break;

         }

         calcB();

         if (strcmp(A, B) == )

         {

             printf("%s is a palindromic number.\n", A);

             break;

         }

         calcC();

         printf("%s + %s = %s\n", A, B, C);

         strcpy(A, C);

     }

     return ;

 }

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