3202. Find the Maximum Length of Valid Subsequence II

 JAVA

• class Solution {
      public int maximumLength(int[] nums, int k) {
          int[][] f = new int[k][k];
          int ans = 0;
          for (int x : nums) {
              x %= k;
              for (int j = 0; j < k; ++j) {
                  int y = (j - x + k) % k;
                  f[x][y] = f[y][x] + 1;
                  ans = Math.max(ans, f[x][y]);
              }
          }
          return ans;
      }
  }

C++

• class Solution {
  public:
      int maximumLength(vector<int>& nums, int k) {
          int f[k][k];
          memset(f, 0, sizeof(f));
          int ans = 0;
          for (int x : nums) {
              x %= k;
              for (int j = 0; j < k; ++j) {
                  int y = (j - x + k) % k;
                  f[x][y] = f[y][x] + 1;
                  ans = max(ans, f[x][y]);
              }
          }
          return ans;
      }
  };