Question

Java

Write a method countStairs that, given a number of blocks, counts and returns the number of stairs you could build with the blocks. Stairs are built in a staircase with one block for the first step, two for the second step, three for the third step, and so on, like this picture which shows * for each block in a staircase:

*
**
***

If you had 5 blocks, you could only build 2 stairs (which requires 1+2 = 3 blocks) and not 3 stairs (which would require 1+2+3 = 6 blocks). Hint: Use a loop which counts up to calculate the total number of blocks needed for successive steps until you surpass the number of blocks given. You may only use two if statements.

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countStairs(0)
countStairs(1)
countStairs(2)
countStairs(3)
countStairs(4)
countStairs(5)
countStairs(6)
countStairs(10)
countStairs(15)

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What I have so far does not work for inputs: 2, 4, 5

public static int countStairs(int blocks) {
int i = 0;
int n = 1;
int count = 0;
while (i < blocks){
i += n;
n++;
}
return n - 1;
}

Answer 1

public static int countStairs(int blocks) {
    int n = 1;
    while (n <= blocks){
        blocks -= n;
        n++;
    }
    return n-1;
}