UVa 1583 Digit Generator(數學)

標籤：acm   uva   小白   數學   



題意 如果a加上a所有數位上的數等於b時 a稱為b的generator  求給定數的最小generator 

給的數n是小於100,000的  考慮到所有數位和最大的數99,999的數位和也才45  因此我們只需要從n-45到n枚舉就行了

#include<cstdio>  #include<cstring>  using namespace std;  int t, n, a, b, ans, l;  int main()  {      scanf ("%d", &t);      while (t--)      {          scanf ("%d", &n);          ans = 0;          for (int i = n-50; i < n; ++i)          {              a = b = i;              while (b)              {                  a += b % 10;                  b /= 10;              }              if (a + b == n)              {                  ans = i;                  break;              }          }          printf ("%d\n", ans);      }      return 0;  } 

For a positive integer N , the digit-sum of N is defined as the sum of N itself and its digits. When M is the digitsum of N , we call N a generator of M .

For example, the digit-sum of 245 is 256 (= 245 + 2 + 4 + 5). Therefore, 245 is a generator of 256.

Not surprisingly, some numbers do not have any generators and some numbers have more than one generator. For example, the generators of 216 are 198 and 207.

You are to write a program to find the smallest generator of the given integer.

Input 

Your program is to read from standard input. The input consists of T test cases. The number of test cases T is given in the first line of the input. Each test case takes one line containing an integer N , 1N100, 000 .

Output 

Your program is to write to standard output. Print exactly one line for each test case. The line is to contain a generator of N for each test case. If N has multiple generators, print the smallest. If N does not have any generators, print 0.

The following shows sample input and output for three test cases.

Sample Input 

3 216 121 2005

Sample Output 

198 0 1979

UVa 1583 Digit Generator(數學)