记录一些常用的函数

*return：返回的是扩大10^accuracy后的商值。
*/
uint32_t accuracy_cal(uint32_t didiv,uint32_t div, uint32_t accuracy){
uint32_t quotient,remainder;
uint32_t ret =0;
uint32_t i;

for(i = 0; i < accuracy + 1; i ++){
quotient = didiv / div;
remainder = didiv % div;
ret = ret*10 + quotient;
didiv = remainder * 10;
}
return ret;
}