Q1_4.java

public class Q1_4 {
  public static void main(String args[]){
    char[] test = {'a',' ','b',' ',' ','c',' ',' ',' ',' ',' ',' '};
    System.out.println(process(test,6));
  }
  
  static String process(char[] array, int length){
    int numberOfSpace = 0;
    for(int i = 0; i<length; i++){
      if(array[i] == ' ')
      numberOfSpace++;
    }
    int retLength = length + 2*numberOfSpace;
    int j = length-1;
    for(int i = retLength-1; i>=0; ){
      if(array[j] == ' '){
        array[i]='0';
        array[i-1]='2';
        array[i-2] ='%';
        i = i-3;
      }
      else{
        array[i] = array[j];
        i--;
      } 
      j--;
    }
    
    return new String(array);
  }
}