Excel 表列序号

// Java solution using Java Stream for converting Excel column title to number
// The approach is similar to the previous solution but utilizes streams to calculate the result.
// We use the IntStream to iterate over the characters, map them to their positional values, and then use reduce to accumulate the result.
import java.util.stream.IntStream;
 
public class Solution {
    public int titleToNumber(String columnTitle) {
        return IntStream.range(0, columnTitle.length())
                .map(i -> columnTitle.charAt(i) - 'A' + 1)
                .reduce(0, (result, charValue) -> result * 26 + charValue);
    }
}