[Algo] 649. String Replace (basic)

Given an original string input, and two strings S and T, replace all occurrences of S in input with T.

Assumptions

• input, S and T are not null, S is not empty string

Examples

• input = "appledogapple", S = "apple", T = "cat", input becomes "catdogcat"
• input = "laicode", S = "code", T = "offer", input becomes "laioffer"

public class Solution {
  public String replace(String input, String source, String target) {
    // Write your solution here
    StringBuilder sb = new StringBuilder();
    int start = 0;
    int match = input.indexOf(source, start);
    while (match != -1) {
      // append end index exclusive
      sb.append(input, start, match).append(target);
      start = match + source.length();
      match = input.indexOf(source, start);
    }
    sb.append(input, start, input.length());
    return sb.toString();
  }
}