comefrom: <awangdev>121. Best Time to Buy and Sell Stock_4.java
code: public int maxProfit(int[] prices) {
          if (prices == null || prices.length == 0) {
              return 0;
          }
          int n = prices.length;
          int[] dp = new int[2];
          dp[0] = Integer.MAX_VALUE;
          int profit = 0;
          for (int i = 1; i <= n; i++) {
              dp[i % 2] = Math.min(dp[(i - 1) % 2], prices[i - 1]);
              profit = Math.max(profit, prices[i - 1] - dp[i % 2]);
          }
          return profit;
      }
masked: public int sample_funcname ( int [ ] var_0 ) {
    if ( var_0 == null || var_0 . length == 0 ) {
      return 0 ;
    }
    int var_4 = var_0 . length ;
    int [ ] var_6 = new int [ 2 ] ;
    var_6 [ 0 ] = Integer . MAX_VALUE ;
    int var_9 = 0 ;
    for ( int var_11 = 1 ;
    var_11 <= var_4 ;
    var_11 ++ ) {
      var_6 [ var_11 % 2 ] = Math . min ( var_6 [ ( var_11 - 1 ) % 2 ] , var_0 [ var_11 - 1 ] ) ;
      var_9 = Math . max ( var_9 , var_0 [ var_11 - 1 ] - var_6 [ var_11 % 2 ] ) ;
    }
    return var_9 ;
  }
  