#Java - Code Snippets for '#Recursion' - 2 code snippet(s) found |
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Sample 1. Write a Program to reverse a string iteratively and recursively | |
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Using String method -
new StringBuffer(str).reverse().toString();
Iterative -
Strategy - Loop through each character of a String from last to first and append the character to StringBuilder / StringBuffer
public static String getReverseString(String str){
StringBuffer strBuffer = new StringBuffer(str.length);
for(int counter=str.length -1 ; counter>=0;counter--){
strBuffer.append(str.charAt(counter));
}
return strBuffer;
}
Recursive -
Strategy - Call the method with substring starting from 2nd character recursively till we have just 1 character.
public static String getReverseString(String str){
if(str.length <= 1){
return str;
}
return (getReverseString(str.subString(1)) + str.charAt(0);
}
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Like Feedback string StringBuffer recursion for loop control statements loop statement stringbuffer.append java.lang.String java.lang.StringBuffer String Manipulation |
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Sample 2. Method to get all files from a directory recursively | |
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List<File> fileList = new ArrayList();
List<File> read(String dir) throws IOException{
File directory = new File(dir);
File[] fList = directory.listFiles();
for(File file:fList){
if(file.isDirectory()){
read(file.getPath());
} else {
fileList.add(file);
}
}
return fileList;
}
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Like Feedback file handling file isDirectory() .getPath() recursion java.io.File |
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