A homicide occurred in a certain place in Japan, and it was often determined through investigation that the murderer must be one of the four suspects

A homicide occurred in a certain place in Japan, and it was often determined through investigation that the murderer must be one of the four suspects.

    Here are the confessions of the four suspects:
    A said: Not me.
    B said: It is C.
    C said: Yes D.
    D said: C is talking nonsense.
    It is known that 3 people told the truth and 1 person told the lie.
    Based on this information, please write a program to determine who the murderer is?

To solve this problem, we must first draw a graph analysis:

 Write a program from the analysis results:

#include<stdio.h>

int main()
{
	char k = 0;    // 设定k是凶手
	for (k = 'A'; k <= 'D'; k++)
	{
		//printf("%c\n", k);
	  //如果（（k不是A）+（k是C）+（k是D）+（k不是D）的结果等于3）----就是三个真话，一个假话
		if (((k != 'A') + (k == 'C') + (k == 'D') + (k != 'D')) == 3)
		{
			printf("凶手是：%c\n", k);  // 满足条件的k就是凶手了
		}
	}
	return 0;
}

The following is the result of running: