Initial commit: C language learning code

翁凯C语言/4/函数原型.c

@@ -0,0 +1,28 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <math.h>
+#include <stdbool.h>
+
+// !函数原型声明
+int num_sum(int begin, int end);
+
+int main()
+{
+    printf("%d\n", num_sum(1, 10));
+    printf("%d\n", num_sum(20, 30));
+    printf("%d\n", num_sum(35, 45));
+
+    return 0;
+}
+
+// !函数定义
+int num_sum(int begin, int end)
+{
+    int sum = 0;
+    for (int i = begin; i <= end; i++)     
+    {
+        sum += i;
+    }
+    return sum;
+}