179 - Largest Number

 C++

• class Solution {
  public:
      string largestNumber(vector<int>& nums) {
          vector<string> vs;
          for (int v : nums) vs.push_back(to_string(v));
          sort(vs.begin(), vs.end(), [](string& a, string& b) {
              return a + b > b + a;
          });
          if (vs[0] == "0") return "0";
          string ans;
          for (string v : vs) ans += v;
          return ans;
      }
  };

JAVA

• class Solution {
      public String largestNumber(int[] nums) {
          List<String> vs = new ArrayList<>();
          for (int v : nums) {
              vs.add(v + "");
          }
          vs.sort((a, b) -> (b + a).compareTo(a + b));
          if ("0".equals(vs.get(0))) {
              return "0";
          }
          return String.join("", vs);
      }
  }