Initial commit: C language learning code

翁凯C语言/3/水仙花数.c

@@ -0,0 +1,57 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <math.h>
+
+int power(int a, int x)	//a的x次方运算
+{	
+	if (x < 0)
+	{
+		printf("输入错误，请重新输入！\n");
+		return -1;
+	}
+	else
+	{
+		int sum = 1;
+		for (int i = 0; i < x; i++)
+		{
+			sum *= a;
+		}
+		return sum;
+	}
+}
+
+int main()
+{
+	int n;
+	printf("请输入一个正整数n（3 ≤ n ≤ 7）：");
+	scanf("%d", &n);
+	
+	if (n < 3 || n > 7)
+	{
+		printf("输入错误，请重新输入！\n");
+	}
+	else
+	{
+		int lower = power(10, n - 1);	//n位数的最小值
+		int upper = power(10, n) - 1;	//n位数的最大值
+
+		for (int num = lower; num <= upper;num++)	//缩小范围，减少运算量
+		{
+			int sum=0;
+			int m = num;
+			while(m>0)
+			{
+				int a = m % 10;
+				sum += power(a,n);
+				m /= 10;
+			}
+			if (num==sum)
+			{
+				printf("%d\n", sum);
+			}
+		}
+	}
+
+	return 0;
+}