Interview 150
Excel Sheet Column Number
- Problem
- LC 171
- File
- interview150_LC171ExcelSheetColumnNumber.java
- Path
- pkg5leetcode/interview150/interview150_LC171ExcelSheetColumnNumber.java
- Package
- pkg5leetcode.interview150
- Command
- java pkg5leetcode/interview150/interview150_LC171ExcelSheetColumnNumber.java
- Approach
- Base-26 from right; A=1 not zero-based.
- Complexity
- Time O(n), Space O(1)
There is no in-browser runner. This is the file from the curriculum, unchanged.
1package pkg5leetcode.interview150;2 3/*4 * Excel Sheet Column Number | LC 1715 * APPROACH: Base-26 from right; A=1 not zero-based.6 * COMPLEXITY: Time O(n), Space O(1)7 */8public class interview150_LC171ExcelSheetColumnNumber {9 static int titleToNumber(String columnTitle) {10 int res = 0;11 for (char c : columnTitle.toCharArray())12 res = res * 26 + (c - 'A' + 1);13 return res;14 }15 16 public static void main(String[] args) {17 check(titleToNumber("A") == 1, "case1");18 check(titleToNumber("AB") == 28, "case2");19 check(titleToNumber("ZY") == 701, "case3");20 System.out.println("all tests passed");21 }22 23 static void check(boolean cond, String name) {24 if (!cond) throw new AssertionError("FAILED: " + name);25 System.out.println(" PASS " + name);26 }27}