comefrom: <awangdev>689. Maximum Sum of 3 Non-Overlapping Subarrays_2.java
code: private int[] calcRight(int[] nums, int[] presum, int k) {
  
          int n = nums.length;
          int[] right = new int[n];
          right[n - k] = n - k;
          for (int i = n - k - 1, total = presum[n] - presum[n - k]; i>= 0; i--) {
              int sum = presum[i + k] - presum[i]; 
              if (sum >= total) {
                  right[i] = i;
                  total = sum;
              } else right[i] = right[i + 1];
          }
          return right;
      }
masked: private int [ ] sample_funcname ( int [ ] var_0 , int [ ] var_1 , int var_2 ) {
    int var_4 = var_0 . length ;
    int [ ] var_5 = new int [ var_4 ] ;
    var_5 [ var_4 - var_2 ] = var_4 - var_2 ;
    for ( int var_7 = var_4 - var_2 - 1 , var_8 = var_1 [ var_4 ] - var_1 [ var_4 - var_2 ] ;
    var_7 >= 0 ;
    var_7 -- ) {
      int var_10 = var_1 [ var_7 + var_2 ] - var_1 [ var_7 ] ;
      if ( var_10 >= var_8 ) {
        var_5 [ var_7 ] = var_7 ;
        var_8 = var_10 ;
      }
      else var_5 [ var_7 ] = var_5 [ var_7 + 1 ] ;
    }
    return var_5 ;
  }
  