comefrom: <awangdev>327. Count of Range Sum_2.java
code: private long[] calcPreSum(int[] nums) {
  
          long[] preSum = new long[nums.length + 1];
          for (int i = 1; i < preSum.length; i++) {
              preSum[i] = preSum[i - 1] + nums[i - 1];
          }
          return preSum;
      }
masked: private long [ ] sample_funcname ( int [ ] var_0 ) {
    long [ ] var_1 = new long [ var_0 . length + 1 ] ;
    for ( int var_2 = 1 ;
    var_2 < var_1 . length ;
    var_2 ++ ) {
      var_1 [ var_2 ] = var_1 [ var_2 - 1 ] + var_0 [ var_2 - 1 ] ;
    }
    return var_1 ;
  }
  