1-5.c
#include <stdio.h> main() { int fahr; for (fahr = 300; fahr >= 0; fahr = fahr - 20) printf("%3d %6.1f\n", fahr, (5.0/9.0)*(fahr-32)); }
$ ./a.out
300 148.9
280 137.8
260 126.7
240 115.6
220 104.4
200 93.3
180 82.2
160 71.1
140 60.0
120 48.9
100 37.8
80 26.7
60 15.6
40 4.4
20 -6.7
0 -17.8
粛々と