zenefits oa - random to generate a random

Posted 2020-06-12

If given a function that generates a random number from 1 to 5, how do you use this function to generate a random number from 1 to 7 with the same probability? (ie. function a has probability 1/5 per number, function b would have probability 1/7).  

 

int sum = 0;
int times = 5;
while(times>0){
　　times--;
　　sum += rand(5);
}

// 5 ~ 25  = 3 *７
return (sum - 2) / 3;