2453. Destroy Sequential Targets

You are given a 0-indexed array nums consisting of positive integers, representing targets on a number line. You are also given an integer space.

You have a machine which can destroy targets. Seeding the machine with some nums[i] allows it to destroy all targets with values that can be represented as nums[i] + c * space, where c is any non-negative integer. You want to destroy the maximum number of targets in nums.

Return the minimum value of nums[i] you can seed the machine with to destroy the maximum number of targets.

class Solution {
public:
    int destroyTargets(vector<int>& nums, int space) {
        int ma = 0, pick = -1;
        unordered_map<int, int> freq;
        unordered_map<int, int> mi;
        for(auto n : nums) {
            int now = n % space;
            if(!mi.count(now)) mi[now] = n;
            mi[now] = min(mi[now], n);
            ++freq[now];
            if(ma < freq[now]) {
                ma = freq[now];
                pick = mi[now];
            } else if(ma == freq[now]) pick = min(pick, mi[now]);
        }
        return pick;
    }
};