c - Why does integer division truncation not occur here? -


i going through examples in k&r, , stumbled upon bit of code:

celcius=5 * (fahr-32) / 9;

the author says can't use 5/9 since integer division truncation lead value of 0.

the program however, outputs 17 answer when fahr=0. calculations, (0-32)/9 should lead -3 (due truncation) , -3*5 = -15, , not -17. why happen?

(0 - 32) first multiplied 5, giving -160. -160 / 9 = -17.


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