1: /* sum_ave01.c sum and average */
 2: #include <stdio.h>
 3: 
 4: /* 関数 sum_ave のプロトタイプ宣言 */
 5: void sum_ave( float, float, float *, float * );
 6: 
 7: 
 8: int main( void ){
 9: 
10:   /* 変数の宣言 */
11:   float a, b;
12:   float y, z;
13: 
14:   a = -1.0, b = 7.0;
15: 
16:   /* 和と平均の計算 */
17:   sum_ave( a, b, &y, &z );
18: 
19:   /* 答えを表示 */
20:   printf( "a = %5.2f\n", a );
21:   printf( "b = %5.2f\n", b );
22:   printf( "a + b = %5.2f\n", y );
23:   printf( "( a + b ) / 2 = %5.2f\n", z );
24:   
25:   return 0;
26:   
27: }
28: 
29: 
30: /* 関数 sum_ave */
31: void sum_ave( float c, float d, float *ptrw, float *ptrx ){
32: 
33:   /* 和を計算 */
34:   *ptrw = c + d;
35: 
36:   /* 平均を計算 */
37:   *ptrx = ( c + d ) / 2.0;
38:   
39: }