问题 : Turing equation

问题 : Turing equation

时间限制: 1 Sec  内存限制: 128 MB
http://218.198.32.182/problem.php?cid=1069&pid=5

题目描述

The fight goes on, whether to store  numbers starting with their most significant digit or their least  significant digit. Sometimes  this  is also called  the  "Endian War". The battleground  dates far back into the early days of computer  science. Joe Stoy,  in his (by the way excellent)  book  "Denotational Semantics", tells following story:

"The decision  which way round the digits run is,  of course, mathematically trivial. Indeed,  one early British computer  had numbers running from right to left (because the  spot on an oscilloscope tube  runs from left to right, but  in serial logic the least significant digits are dealt with first). Turing used to mystify audiences at public lectures when, quite by accident, he would slip into this mode even for decimal arithmetic, and write  things  like 73+42=16.  The next version of  the machine was  made more conventional simply  by crossing the x-deflection wires:  this,  however, worried the engineers, whose waveforms  were all backwards. That problem was in turn solved by providing a little window so that the engineers (who tended to be behind the computer anyway) could view the oscilloscope screen from the back.

You will play the role of the audience and judge on the truth value of Turing's equations.

输入

The input contains several test cases. Each specifies on a single line a Turing equation. A Turing equation has the form "a+b=c", where a, b, c are numbers made up of the digits 0,...,9. Each number will consist of at most 7 digits. This includes possible leading or trailing zeros. The equation "0+0=0" will finish the input and has to be processed, too. The equations will not contain any spaces.

输出

For each test case generate a line containing the word "TRUE" or the word "FALSE", if the equation is true or false, respectively, in Turing's interpretation, i.e. the numbers being read backwards.

样例输入

73+42=16

5+8=13

0001000+000200=00030

0+0=0

样例输出

TRUE

FALSE

TRUE

解题思路：

就是讲每个数取逆序数字，然后相加，看是否成立。 输出0+0=0的时候结束。

源代码：

# include 
# include 


int main(void)
{
	char a[100];
	while (~ scanf("%s", a))
	{
		int i, d = strlen(a), c, j, k;
		int sum = 0, sum1 = 0, sum2 = 0;
		c = 1;
		for (i = 0; a[i] != '+'; i ++)
		{
			sum += (a[i] - '0')*c;
			c *= 10;
		}	
		c = 1;
		for (j = i+1; a[j] != '='; j ++)
		{
			sum1 += (a[j] - '0')*c;
			c *= 10;
		}
		c = 1;
		for (k = j+1; a[k] != '\0'; k ++)
		{
			sum2 += (a[k] - '0')*c;
			c *= 10;
		}
		if (sum == 0 && sum1 == 0 && sum2 == 0)
		break;
		if (sum + sum1 == sum2)
		printf("TRUE\n");
		else
		printf("FALSE\n");
		
	}
	return 0;
}