java - How do I generate random numbers in an array that add up to a defined total? -

i need randomly generate array 7 slots in java. these slots must have value of @ least 1, combined, have total value of defined number. need int value, no 1.5 or 0.9816465684646 numbers. example:

int a=10;  int[] ar = new int[7] ar[0] = 1 ar[1] = 1 ar[2] = 2 ar[3] = 2 ar[4] = 1 ar[5] = 2 ar[6] = 1 

i want generate that, if int a=15, numbers total 15 in order

the standard way generate n random numbers add given sum think of sum number line, generate n-1 random points on line, sort them, use differences between points final values. minimum 1, start subtracting n sum, run algorithm given, add 1 each segment.

public class rand {     public static void main(string[] args) {         int count = 8;         int sum = 100;         java.util.random g = new java.util.random();          int vals[] = new int[count];         sum -= count;          (int = 0; < count-1; ++i) {             vals[i] = g.nextint(sum);         }         vals[count-1] = sum;          java.util.arrays.sort(vals);         (int = count-1; > 0; --i) {             vals[i] -= vals[i-1];         }         (int = 0; < count; ++i) { ++vals[i]; }          (int = 0; < count; ++i) {             system.out.printf("%4d", vals[i]);         }         system.out.printf("\n");     } }