add solution of HW4

hws/yelp_businesses/Business.cpp

@@ -0,0 +1,127 @@
+#include <string>
+#include <cctype>
+#include <cstdlib>
+
+#include "Business.h"
+
+//extracts a string value for the given field
+std::string extractJsonString(const std::string &line, const std::string &field) {
+    std::string pattern = "\"" + field + "\":";
+    size_t pos = line.find(pattern);
+    if (pos == std::string::npos) {return "";} //in case pattern not found
+    pos += pattern.length();
+    //skip any whitespace
+    while (pos < line.size() && isspace(line[pos])) {pos++;}
+    if (pos >= line.size() || line[pos] != '\"') {return "";} //in case the opening quote is not found
+    pos++;
+    //skip the opening quote
+    size_t endPos = line.find("\"", pos);
+    if (endPos == std::string::npos) {return "";} //in case the closing quote is not found
+    return line.substr(pos, endPos - pos);
+}
+
+//extracts an integer value for the given field
+int extractJsonInt(const std::string &line, const std::string &field) {
+    std::string pattern = "\"" + field + "\":";
+    size_t pos = line.find(pattern);
+    if (pos == std::string::npos) {return -1;} //in case the pattern is not found
+    pos += pattern.length();
+    //skip any whitespace
+    while (pos < line.size() && isspace(line[pos])) {pos++;}
+    size_t endPos = pos;
+    //skip the negative sign
+    if (line[endPos] == '-') {endPos++;}
+    //skip the digits
+    while (endPos < line.size() && isdigit(line[endPos])) {endPos++;}
+    std::string numStr = line.substr(pos, endPos - pos);
+    int value = std::stoi(numStr);
+    if (value == 0) {return -1;} //in case the number is not found
+    return value;
+}
+
+//extracts a double value for the given field
+double extractJsonDouble(const std::string &line, const std::string &field) {
+    std::string pattern = "\"" + field + "\":";
+    size_t pos = line.find(pattern);
+    if (pos == std::string::npos) {return 0.0;} // in case the pattern is not found
+    pos += pattern.length();
+    //skip any whitespace
+    while (pos < line.size() && isspace(line[pos])) {pos++;}
+    if (line[pos] == '\"') {
+        //in case the data is quoted
+        pos++;
+        size_t endPos = line.find("\"", pos);
+        if (endPos == std::string::npos) {return 0.0;}
+        std::string numStr = line.substr(pos, endPos - pos);
+        double value = std::stod(numStr);
+        if (value == 0.0) {return 0.0;} //in case the number is not found
+        return value;
+    } else {
+        //in case the data is not quoted
+        size_t endPos = pos;
+        while (endPos < line.size() && (isdigit(line[endPos]) || line[endPos] == '.' || line[endPos]=='-')) {
+            endPos++;
+        }
+        std::string numStr = line.substr(pos, endPos - pos);
+        double value = std::stod(numStr);
+        if (value == 0.0) {return 0.0;} //in case the number is not found
+        return value;
+    }
+}
+
+//extracts a price value for the given field
+int extractJsonPrice(const std::string &line, const std::string &field) {
+    std::string pattern = "\"" + field + "\":";
+    size_t pos = line.find(pattern);
+    if (pos == std::string::npos) {return -1;} //in case the pattern is not found
+    pos += pattern.length();
+    //skip any whitespace
+    while (pos < line.size() && isspace(line[pos])) {pos++;}
+    if (line[pos] == '\"') {
+        pos++;
+        size_t endPos = line.find("\"", pos);
+        if (endPos == std::string::npos) {return -1;}
+        std::string numStr = line.substr(pos, endPos - pos);
+        if (numStr == "None") {return -1;} //in case the number is not found
+        return std::stoi(numStr);
+    } else {
+        size_t endPos = pos;
+        while (endPos < line.size() && (isdigit(line[endPos]) || line[endPos]=='-')) {
+            endPos++;
+        }
+        std::string numStr = line.substr(pos, endPos - pos);
+        if (numStr == "None") {return -1;} //in case the number is not found
+        return std::stoi(numStr);
+    }
+}
+
+//load the business data from a JSON line
+Business::Business(const std::string &jsonLine) {
+    name         = extractJsonString(jsonLine, "name");
+    categories   = extractJsonString(jsonLine, "categories");
+    rating       = extractJsonDouble(jsonLine, "stars");
+    price        = extractJsonPrice(jsonLine, "RestaurantsPriceRange2");
+    review_count = extractJsonInt(jsonLine, "review_count");
+    city         = extractJsonString(jsonLine, "city");
+    postal_code  = extractJsonString(jsonLine, "postal_code");
+}
+
+std::string Business::getName() const {return name;}
+std::string Business::getCategories() const {return categories;}
+double Business::getRating() const {return rating;}
+int Business::getPrice() const {return price;}
+int Business::getReviewCount() const {return review_count;}
+std::string Business::getCity() const {return city;}
+std::string Business::getPostalCode() const {return postal_code;}
+
+//returns a string representing the star rating.
+std::string Business::getStarString() const {
+    int fullStars = static_cast<int>(rating);
+    double fraction = rating - fullStars;
+    std::string stars;
+    for (int i = 0; i < fullStars; ++i)
+        stars += "\u2605";
+    if (fraction >= 0.5)
+        stars += "\u00BD";
+    return stars;
+}

hws/yelp_businesses/Business.h

@@ -0,0 +1,31 @@
+#ifndef BUSINESS_H
+#define BUSINESS_H
+
+#include <string>
+
+class Business {
+public:
+    //constructs a Business by parsing a JSON-formatted line
+    Business(const std::string &jsonLine);
+    //Accessors
+    std::string getName() const;
+    std::string getCategories() const;
+    double      getRating() const;
+    int         getPrice() const;
+    int         getReviewCount() const;
+    std::string getCity() const;
+    std::string getPostalCode() const;
+    //returns a string representation of the star rating
+    std::string getStarString() const;
+    
+private:
+    std::string name;
+    std::string categories;
+    double      rating;
+    int         price;
+    int         review_count;
+    std::string city;
+    std::string postal_code;
+};
+
+#endif // BUSINESS_H

hws/yelp_businesses/README.txt

@@ -1,7 +1,7 @@
 HOMEWORK 4: Yelp Businesses
 
 
-NAME:  < insert name >
+NAME:  Jinshan Zhou
 
 
 COLLABORATORS AND OTHER RESOURCES:
@@ -10,13 +10,14 @@ List the names of everyone you talked to about this assignment
 LMS, etc.), and all of the resources (books, online reference
 material, etc.) you consulted in completing this assignment.
 
-< insert collaborators / resources >
+Not really, but when I handle the list, I check many lab examples. Also, I check the
+sstream example from alb and my previous homework as well.
 
 Remember: Your implementation for this assignment must be done on your
 own, as described in "Academic Integrity for Homework" handout.
 
 
-ESTIMATE OF # OF HOURS SPENT ON THIS ASSIGNMENT:  < insert # hours >
+ESTIMATE OF # OF HOURS SPENT ON THIS ASSIGNMENT:  13
 
 
 MISC. COMMENTS TO GRADER:
@@ -33,4 +34,9 @@ What parts of the assignment did you find challenging? Is there anything that
 finally "clicked" for you in the process of working on this assignment? How well
 did the development and testing process go for you?
 
-< insert reflection >
+I just start writing the code and implementation directly. Then, I found there are
+a few given codes on the end instruction. But, it's too late for me. I didn't fully
+read through the instruction at the beginning. Which brings me some extra work.
+When I realize that, other parts of my code already depends on my extract JSON functions.
+So, I have to keep writing on top of that. If, I can do this again, I will check the
+instruction in detail and find if there are useful cases.

hws/yelp_businesses/nybusninesses.cpp

@@ -0,0 +1,93 @@
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <string>
+#include <list>
+#include <vector>
+
+#include "Business.h"
+
+int main(int argc, char* argv[]) {
+    if (argc < 5) {
+        std::cerr << "Usage: " << argv[0] 
+                  << " input.json output.txt zipcode [categories...]" 
+                  << std::endl;
+        return 1;
+    }
+    //load the arguments
+    std::string inputFile  = argv[1];
+    std::string outputFile = argv[2];
+    std::string zipcode    = argv[3];
+    //read all categories from arguments
+    std::vector<std::string> searchCategories;
+    for (int i = 4; i < argc; ++i) {
+        searchCategories.push_back(argv[i]);
+    }
+    //open the input file
+    std::ifstream inFile(inputFile.c_str());
+    if (!inFile) {
+        std::cerr << "Error: Could not open input file: " 
+                  << inputFile << std::endl;
+        return 1;
+    }
+    //open the output file
+    std::ofstream outFile(outputFile.c_str());
+    if (!outFile) {
+        std::cerr << "Error: Could not open output file: " 
+                  << outputFile << std::endl;
+        return 1;
+    }
+    //read each line and create a Business object if it matches the zipcode and at least one search category
+    std::list<Business> matchingBusinesses;
+    std::string line;
+    while (std::getline(inFile, line)) {
+        Business biz(line);
+        //check zipcode
+        if (biz.getPostalCode() != zipcode)
+            continue;
+        //check categories: at least one category must be found
+        bool categoryMatch = false;
+        std::string bizCategories = biz.getCategories();
+        for (std::vector<std::string>::const_iterator catIt = searchCategories.begin();
+             catIt != searchCategories.end(); ++catIt) {
+            if (bizCategories.find(*catIt) != std::string::npos) {
+                categoryMatch = true;
+                break;
+            }
+        }
+        if (categoryMatch) {
+            matchingBusinesses.push_back(biz);
+        }
+    }
+    //sort the list by rating in descending order
+    matchingBusinesses.sort([](const Business &a, const Business &b) {
+        return a.getRating() > b.getRating();
+    });
+    //output the results in a format similar to Yelp.
+    if (matchingBusinesses.empty()) {
+        outFile << "Sorry, we couldn't find any results" << std::endl;
+    } else {
+        int index = 1;
+        for (std::list<Business>::const_iterator it = matchingBusinesses.begin();
+             it != matchingBusinesses.end(); ++it) {
+            outFile << "=====================" << std::endl;
+            //add line 1: Index and Business Name
+            outFile << index << ". " << it->getName() << std::endl;
+            //add line 2: Star rating, numeric rating, and review count
+            outFile << it->getStarString() << " " << it->getRating() 
+                    << " (" << it->getReviewCount() << " reviews)" << std::endl;
+            //add line 3: City and then the price range (if available)
+            outFile << it->getCity() << " ";
+            if (it->getPrice() != -1) {
+                for (int i = 0; i < it->getPrice(); ++i)
+                    outFile << "$";
+            }
+            outFile << std::endl;
+            //add line 4: Categories
+            outFile << it->getCategories() << std::endl;
+            index++;
+        }
+        outFile << "=====================" << std::endl;
+    }
+    return 0;
+}