Problem:
We have triangle made of blocks. The topmost row has 1 block, the next row down has 2 blocks, the next row has 3 blocks, and so on. Compute recursively (no loops or multiplication) the total number of blocks in such a triangle with the given number of rows.
triangle(0) → 0
triangle(1) → 1
triangle(2) → 3
Solution:
public int triangle(int rows) {
if (rows == 0) return 0;
return rows + triangle(rows-1);
}
this is also the summation from i = 0 to i = n of i, so an alternative solution to the problem is simply n*(n+1)/2
ReplyDeletepublic int triangle(int rows) {
ReplyDeletereturn (rows ==0)? 0 : triangle(rows-1)+rows;
}
same result
ReplyDeletepublic int triangle(int rows) {
if(rows == 0) {
return 0;
}
return rows + triangle(rows - 1);
}
return rows==0?0:rows+triangle(rows-1);
ReplyDelete