925. Long Pressed Name | zhengxingxing

Method 1

Your friend is typing his name into a keyboard. Sometimes, when typing a character c, the key might get long pressed, and the character will be typed 1 or more times.
You examine the typed characters of the keyboard. Return True if it is possible that it was your friends name, with some characters (possibly none) being long pressed.

Example 1

Input: name = "alex", typed = "aaleex"
Output: true
Explanation: 'a' and 'e' in 'alex' were long pressed.

Example 2

Input: name = "saeed", typed = "ssaaedd"
Output: false
Explanation: 'e' must have been pressed twice, but it was not in the typed output.

Method 1

【O(n + m) time | O(1) space】

package Leetcode.TwoPointer.DoubleSeqTwoPointers;

/**
 * @author zhengxingxing
 * @date 2025/03/09
 */
public class LongPressedName {
   
    public static boolean isLongPressedName(String name, String typed) {
        // Initialize two pointers: i for name string, j for typed string
        int i = 0;  // pointer for name string
        int j = 0;  // pointer for typed string

        while (j < typed.length()) {
            // Case 1: Characters match - advance both pointers
            if (i < name.length() && name.charAt(i) == typed.charAt(j)) {
                i++;
                j++;
            }
            // Case 2: Long-pressed character - check if current char matches previous char
            else if (j > 0 && typed.charAt(j) == typed.charAt(j - 1)) {
                j++;
            }
            // Case 3: Neither matches nor long-pressed - invalid input
            else {
                return false;
            }
        }

        // Final check: ensure we've matched all characters in name
        return i == name.length();
    }
    
    public static void main(String[] args) {
        // Test Case 1: Normal long-press scenario
        String name1 = "alex";
        String typed1 = "aaleex";
        System.out.println("Test Case 1 Result: " +
                isLongPressedName(name1, typed1));  // Expected output: true

        // Test Case 2: Invalid long-press scenario
        String name2 = "saeed";
        String typed2 = "ssaaedd";
        System.out.println("Test Case 2 Result: " +
                isLongPressedName(name2, typed2));  // Expected output: false

        // Test Case 3: Exact match scenario
        String name3 = "alex";
        String typed3 = "alex";
        System.out.println("Test Case 3 Result: " +
                isLongPressedName(name3, typed3));  // Expected output: true

        // Test Case 4: Typed string shorter than name
        String name4 = "alex";
        String typed4 = "ale";
        System.out.println("Test Case 4 Result: " +
                isLongPressedName(name4, typed4));  // Expected output: false

        // Test Case 5: Completely different strings
        String name5 = "alex";
        String typed5 = "bbbb";
        System.out.println("Test Case 5 Result: " +
                isLongPressedName(name5, typed5));  // Expected output: false
    }
}

Method 1

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