用减奇数次数的方法，求一个数的近似平方根，这个平方根是一个整数。如求17的平方根，可以用17相继减去奇数1、3、5、7、…，当结果为 负数时停止，即：



17-1-3-5-7-9＜0

可以看出，17在减去5次奇数后结果变为负数，可以近似认为17的平方根在4与5之间，计算NUM的平方根，如果NUM=17，则ANS中保存结果4。-　With an odd number of reduction method, find the approximate square root of a number, the square root of an integer. Such as for the square root of 17, you can use 17 have less odd 1,3,5,7, ..., stopping when the result is negative, namely:　17-1-3-5-7-9 < 0　can be seen , 17, after subtracting the result becomes 5 times the odd negative, can be approximated by the square root of that 17 between the 4 and 5 to calculate the square root of NUM, if NUM = 17, then save the results 4 ANS.