Problem
Given a positive integer n, find the sum of all integers in the range [1, n] inclusive that are divisible by 3, 5, or 7.
Return an integer denoting the sum of all numbers in the given range satisfying the constraint.
Example 1:
Input: n = 7
Output: 21
Explanation: Numbers in the range [1, 7] that are divisible by 3, 5, or 7 are 3, 5, 6, 7. The sum of these numbers is 21.
Example 2:
Input: n = 10
Output: 40
Explanation: Numbers in the range [1, 10] that are divisible by 3, 5, or 7 are 3, 5, 6, 7, 9, 10. The sum of these numbers is 40.
Example 3:
Input: n = 9
Output: 30
Explanation: Numbers in the range [1, 9] that are divisible by 3, 5, or 7 are 3, 5, 6, 7, 9. The sum of these numbers is 30.
Constraints:
1 <= n <= 103
Solution (Java)
class Solution {
public int sumOfMultiples(int n) {
int ans = 0;
for(int i = 1; i<=n; i++) if(i%3==0 || i%5==0 || i%7==0) ans+=i;
return ans;
}
}
Explain:
nope.
Complexity:
- Time complexity : O(n).
- Space complexity : O(n).