Official algorithmic problem description and constraints.
You are given three positive integers num1, num2, and num3.
The key of num1, num2, and num3 is defined as a four-digit number such that:
ith digit (1 <= i <= 4) of the key is generated by taking the smallest digit among the ith digits of num1, num2, and num3.Return the key of the three numbers without leading zeros (if any).
Example 1:
Input: num1 = 1, num2 = 10, num3 = 1000
Output: 0
Explanation:
On padding, num1 becomes "0001", num2 becomes "0010", and num3 remains "1000".
1st digit of the key is min(0, 0, 1).2nd digit of the key is min(0, 0, 0).3rd digit of the key is min(0, 1, 0).4th digit of the key is min(1, 0, 0).Hence, the key is "0000", i.e. 0.
Example 2:
Input: num1 = 987, num2 = 879, num3 = 798
Output: 777
Example 3:
Input: num1 = 1, num2 = 2, num3 = 3
Output: 1
Constraints:
1 <= num1, num2, num3 <= 9999Detailed video explanations, mathematical intuition, and clean C++ implementation code.