Problem of the Day
A new programming or logic puzzle every Mon-Fri

Welcome back to another fantastic Monday!

Today's objective is to write a method that takes a given string and replaces all occurrences of that string with another string and returns the number of replacements made. For instance, given the string "problem of the day" and a replacement value of " ", the final result would be "problem-of-the-day" with a return value of 3. If your language of choice doesn't support pass by reference of strings feel free to return multiple values.

Comments:

• Nick Krichevsky - 10 years, 6 months ago

  C++ solution using the magic of pointers!

  #include <iostream>
  #include <string>
  
  using namespace std;
  int stringReplace(string &s,char replace, char replacment);
  int main(){
      string q = "Hello!!!";
      int j = stringReplace(q,'!','.');
      cout<<q<<endl;
      cout<<"Replaced "<<j<<" chars."<<endl;
  }
  
  int stringReplace(string &s,char replace, char replacment){
      int replaced = 0;
      for (int i=0; i<s.length(); i++){
          char c = s.c_str()[i];
          if (c==replace){
              s[i]=replacment;
              replaced++;
          }
      }
      return replaced;
  }
  

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• Anonymous - 10 years, 6 months ago

  #python 2.7
  def count_replace(sentence, replacestring):
      a = sentence.count(replacestring)
      b = sentence.replace(replacestring, "-")
      print b
      return a
  

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• Mre64 - 10 years, 6 months ago

  /* Mre64 6/16/14

  ''If I were a single man, I might ask that mummy out. That's a good-looking mummy.''
      -Bill Clinton, mummy exhibit at the National Geographic museum
  

  */ import java.util.ArrayList; import java.util.Arrays; import java.util.Collections;

  public class ReplaceString {

  public static void main(String[] args) {
  //the sample string
  String str = "this is is is the string to replace is";
  //call replace function
  findAndReplaceString(str, "is", "not is");
  }
  private static void findAndReplaceString(String str,String toFind, String toReplace){
      //add contents to an arrayList
      ArrayList <String> myList =  new ArrayList<String>(Arrays.asList(str.split(" ")));
      //call the replace method
      replace(myList, toFind, toReplace);
  }
  private static void replace(ArrayList list, String toFind, String toReplace){
          // see if the word your looking for exists
          if(list.contains(toFind)){
              int freq = Collections.frequency(list, toFind);
              Collections.replaceAll(list, toFind, toReplace);
          System.out.println(list.toString() + " frequency: " + freq);
          }else{
              System.out.println("404 NOT FOUND");
      }
  }
  

  }

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• Anonymous - 10 years, 6 months ago

  #python 2.7
  def str_replace(string,replace,substitute):
      return ( substitute.join(string.split(replace)) , len(string.split(replace))-1 )
  print str_replace("problem of the day"," ","-")
  

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