Question

Coding Snippets

Answer 1

`Stop Watch Code Snippet`
```
#define MAX_ROUNDTRIP_COUNT 32

typedef struct stopWatch_s {
struct timeval eachTime[MAX_ROUNDTRIP_COUNT+1];
uint16_t roundTripCount;
} stopWatch_t;

void stopWatch_start(stopWatch_t *stopWatch) {
stopWatch->roundTripCount = 0;
gettimeofday(stopWatch->eachTime, NULL);
}

int stopWatch_createRoundTrip(stopWatch_t *stopWatch) {
if ( !timerisset(&stopWatch->eachTime[0]) ) return -1;

if(stopWatch->roundTripCount >= MAX_ROUNDTRIP_COUNT) {
fprintf(stderr, \\"RoundtripCount of %d reached\n\\", MAX_ROUNDTRIP_COUNT);
return -1;
}

stopWatch->roundTripCount += 1;
gettimeofday(&stopWatch->eachTime[stopWatch->roundTripCount], NULL);
return 0;
}

int stopWatch_printLatestTime(stopWatch_t *stopWatch) {
if ( !timerisset(&stopWatch->eachTime[0]) ) return -1;

struct timeval timeFromStart, timeFromLastRoundtrip;
gettimeofday(&timeFromStart, NULL);
gettimeofday(&timeFromLastRoundtrip, NULL);

/* calculate time deltas */
timersub(&timeFromStart, &stopWatch->eachTime[0], &timeFromStart);
if( stopWatch->roundTripCount == 0 ) {
timerclear(&timeFromLastRoundtrip);
} else {
timersub(&stopWatch->eachTime[stopWatch->roundTripCount],
&stopWatch->eachTime[stopWatch->roundTripCount-1],
&timeFromLastRoundtrip);
}

printf(\\"#%d delta:%ld.%06ld, sum:%ld.%06ld\n\\", stopWatch->roundTripCount, timeFromLastRoundtrip.tv_sec, timeFromLastRoundtrip.tv_usec, timeFromStart.tv_sec, timeFromStart.tv_usec); return 0; } ```

Answer 2

`Tic Tac Toe`
```
/* xo.o
*
* Created by ptrs on 2012-10-08
*
* Copyright (c) 2012 Petar Stupar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<unistd.h>

#define OK 0
#define MOVE_MADE 1
#define OUT_OF_RANGE 2
#define WINNER 3
#define EXIT 666

char player[] = {'O', 'X'};
char grid[3][3][2];
int computer = 0;

int wins[] = {0, 0, 0, 0, 0, 0, 0, 0}; /* There are only 8 possible wins.
Three horizontal, three vertical,
and two diagonal. These are shown
by marking the fields in this array */

void format_grid(){
int x, y;
char ch = '\0';

for(x = 0, y = 0; x < 3; x++){
while(y < 3){
grid[x][y][0] = ' ';
grid[x][y][1] = ch;
y++;
}
y = 0;
}
}

void print_grid(){
int x, y;

printf("\t\t .0.1.2.Y\n");
for(x = 0, y = 0; x < 3; x++){
while(y < 3){
if(y == 0)
printf("\t\t%i", x);
printf("|%s", grid[x][y]);
y++;
}
printf("|\n");
y = 0;
}
printf("\t\tX\n");
}

int is_winner(char ch){
int x, y;
int count;

/* Horizontal check */
for(x = 0, y = 0, count = 0; x < 3; x++){
while(y < 3){
if(grid[x][y][0] == ch){
count++;
}
y++;
}
if(count == 3)
return WINNER;
else
count = 0;
y = 0;
}

/* Vertical check */
for(x = 0, y = 0, count = 0; y < 3; y++){
while(x < 3){
if(grid[x][y][0] == ch){
count++;
}
x++;
}
if(count == 3)
return WINNER;
else
count = 0;
x = 0;
}

/* Diagonal checks */
if(grid[0][0][0] == ch && grid[1][1][0] == ch && grid[2][2][0] == ch)
return WINNER;
if(grid[2][0][0] == ch && grid[1][1][0] == ch && grid[0][2][0] == ch)
return WINNER;

return OK;
}

int maxarrey(){
int i, ti, tn, n;
for(i = 0, ti = tn = 0; i < 8; i++){
if(wins > tn){ tn = wins; ti = i; } if(wins == tn && wins > 0){ for(n = 0; n < 3; n++){ if(i >= 0 && i <= 2){ if(grid[n][0] == ' '){ ti = i; tn = wins; } } if(i >= 3 && i <= 5){ if(grid[n][0] == ' '){ ti = i; tn = wins; } } if(i == 6 && (grid[0][0][0] == ' ' || grid[1][1][0] == ' ' || grid[2][2][0] == ' ')){ ti = i; tn = wins; } if(i == 7 && (grid[0][2][0] == ' ' || grid[1][1][0] == ' ' || grid[2][0][0] == ' ')){ ti = i; tn = wins; } } } } return ti; } int minarrey(){ int i, ti, tn, n; for(i = 0, ti = tn = 0; i < 8; i++){ if(wins < tn){ tn = wins; ti = i; } if(wins == tn && wins < 0){ for(n = 0; n < 3; n++){ if(i >= 0 && i <= 2){ if(grid[n][0] == ' '){ ti = i; tn = wins; } } if(i >= 3 && i <= 5){ if(grid[n][0] == ' '){ ti = i; tn = wins; } } if(i == 6 && (grid[0][0][0] == ' ' || grid[1][1][0] == ' ' || grid[2][2][0] == ' ')){ ti = i; tn = wins; } if(i == 7 && (grid[0][2][0] == ' ' || grid[1][1][0] == ' ' || grid[2][0][0] == ' ')){ ti = i; tn = wins; } } } } return ti; } void computer_move(int *x, int *y){ int tmp_x, tmp_y; int max, min, n; max = maxarrey(); min = minarrey(); if(wins[min] == -2 && wins[max] < 2){ /* Is the user winning?? */ if(min >= 0 && min <= 2){ tmp_x = min; for(n = 0; n < 3; n++){ if(grid[tmp_x][n][0] == ' '){ tmp_y = n; } } } else if(min >= 3 && min <= 5){ tmp_y = min - 3; for(n = 0; n < 3; n++){ if(grid[n][tmp_y][0] == ' '){ tmp_x = n; } /* else tmp_x = n; */ } if(tmp_y == 2) tmp_x--; } else if(min == 6){ if(grid[0][0][0] == ' '){ tmp_x = 0; tmp_y = 0; } else if(grid[1][1][0] == ' '){ tmp_x = 1; tmp_y = 1; } else if(grid[2][2][0] == ' '){ tmp_x = 2; tmp_y = 2; } } else if(min == 7){ if(grid[2][0][0] == ' '){ tmp_x = 2; tmp_y = 0; } else if(grid[1][1][0] == ' '){ tmp_x = 1; tmp_y = 1; } else if(grid[0][2][0] == ' '){ tmp_x = 2; tmp_y = 2; } } } else{ /* User is not winning */ if(max >= 0 && max <= 2){ tmp_x = max; for(n = 0; n < 3; n++){ if(grid[tmp_x][n][0] == ' '){ tmp_y = n; } } } else if(max >= 2 && max <= 5){ tmp_y = max; for(n = 0; n < 3; n++){ if(grid[n][tmp_y][0] == ' '){ tmp_x = n; } } } else if(max == 6){ if(grid[2][0][0] == ' '){ tmp_x = 0; tmp_y = 0; } else if(grid[1][1][0] == ' '){ tmp_x = 1; tmp_y = 1; } else if(grid[0][2][0] == ' '){ tmp_x = 2; tmp_y = 2; } } else if(max == 7){ if(grid[0][0][0] == ' '){ tmp_x = 0; tmp_y = 0; } else if(grid[1][1][0] == ' '){ tmp_x = 1; tmp_y = 1; } else if(grid[2][2][0] == ' '){ tmp_x = 2; tmp_y = 2; } } } *x = tmp_x; *y = tmp_y; wins[*x] = wins[*x] + 1; wins[(*y + 3)] = wins[(*y + 3)] + 1; if(*x == 1 && *y == 1){ wins[6] += 1; wins[7] += 1; } if((*x == 0 && *y == 0) || (*x == 2 && *y == 2)){ wins[6] += 1; } if((*x == 0 && *y == 2) || (*x == 2 && *y == 0)){ wins[7] += 1; } } int make_move(char ch){ int mov_x, mov_y; if(computer == 1 && ch == 'O'){ computer_move(&mov_x, &mov_y); grid[mov_x][mov_y][0] = ch; return is_winner(ch); } else{ printf("Enter x and y coordinates separated by a comma (ex. 1,2) or -1 to exit: "); scanf("%i,%i", &mov_x, &mov_y); if(mov_x == -1 && mov_y == -1) return EXIT; if((mov_x >= 0 && mov_x <= 2) && (mov_y >= 0 && mov_y <= 2)){ if(grid[mov_x][mov_y][0] == ' '){ grid[mov_x][mov_y][0] = ch; wins[mov_x] -= 1; wins[(mov_y + 3)] -= 1; if(mov_x == 1 && mov_y == 1){ wins[6] -= 1; wins[7] -= 1; } if((mov_x == 0 && mov_y == 0) || (mov_x == 2 && mov_y == 2)){ wins[6] -= 1; } if((mov_x == 0 && mov_y == 2) || (mov_x == 2 && mov_y == 0)){ wins[7] -= 1; } return is_winner(ch); } else{ return MOVE_MADE; } } else{ return OUT_OF_RANGE; } } return is_winner(ch); } int main(int argc, char *argv[]){ int move = 1; int winner = 0; int outcome; char sw; while((sw = getopt(argc, argv, "c")) != EOF){ switch(sw){ case 'c': computer = 1; } } format_grid(); print_grid(); while(move < 9){ while(move <= 9 && (outcome = make_move(player[move % 2])) == OK){ print_grid(); move++; } if(outcome == MOVE_MADE){ printf("That move was already made. Try again.\n"); continue; } if(outcome == OUT_OF_RANGE){ printf("No such field. Out of range. Try again.\n"); continue; } if(outcome == WINNER){ print_grid(); printf("the WINNER is: %c\n", player[move % 2]); return 0; } if(outcome == EXIT){ return 0; } if(move >= 9){ printf("No winner...\n"); return 0; } } } ```

Answer 3

`Simple Clock`
```
#include<stdio.h>
#include<time.h>
#include<windows.h>
#include <stdlib.h>

int main()
{
struct tm *tmp;
time_t s;

for(;;)
{
s = time(NULL);
tmp = localtime(&t);

printf("%d:%0d:%d\n",tmp->tm_hour,tmp->tm_min,tmp->tm_sec);

Sleep(1000);

system ("cls");

}


return 0;
}

Answer 4

`Calendar`
```
#include <iostream>
#include <iomanip>

bool isLeapYear( unsigned int& ); //checks if 'year' is leap year
unsigned int firstDayOfJanuary( unsigned int& year );
unsigned int numOfDaysInMonth( unsigned int , unsigned int& ); // takes the number of the month, and 'year' as arguments
void printHeader( unsigned int ); //takes the number of the month, and the first day, prints, and updates
void printMonth( unsigned int , unsigned int& ); //takes number of days in month, and reference to 'firstDayInCurrentMonth' so it updates after every call
void skip( unsigned int ); //prints the specified amount of spaces

int main() {
unsigned int year , firstDayInCurrentMonth;
std::cout << "Calendar year? ";
std::cin >> year;
std::cout << "\n";
firstDayInCurrentMonth = firstDayOfJanuary( year );
skip(9);
std::cout << year << "\n";
for ( unsigned int currentMonth = 1 ; currentMonth <= 12 ; currentMonth++ ) {
printHeader( currentMonth );
printMonth( numOfDaysInMonth( currentMonth , year ) , firstDayInCurrentMonth );
std::cout << "\n\n\n";
}
std::cout << "Press Enter to Exit...";
std::cin.ignore();
std::cin.get();
}

bool isLeapYear( unsigned int& year ) { //if number is multiple of 4 and is either multiple of 400 or not multiple of 100, is leap year
return ( year % 4 == 0 ) && ( year % 100 != 0 || year % 400 == 0 );
}

unsigned int firstDayOfJanuary( unsigned int& year ) {
/* "( 97 * year - 97 ) / 400" is the simplification of:

x1 = (year - 1)/ 4;
x2 = (year - 1)/ 100;
x3 = (year - 1)/ 400;
day_start = (year + x1 - x2 + x3) % 7;

after each value is plugged in
*/

return ( year + ( 97 * year - 97 ) / 400 ) % 7;
}

unsigned int numOfDaysInMonth( unsigned int m , unsigned int& year ) {
if ( m == 2 )
return isLeapYear( year ) ? 29 : 28; //if month is February, return correct number based on whether it is leap year
else
return 30 + ( m % 2 ); //otherwise return 31 if month number is odd, 30 if month number is even
}

void printHeader( unsigned int m ) {
skip( 7 );

if ( m == 1 ) std::cout << "January";
else if ( m == 2 ) std::cout << "February";
else if ( m == 3 ) std::cout << "March";
else if ( m == 4 ) std::cout << "April";
else if ( m == 5 ) std::cout << "May";
else if ( m == 6 ) std::cout << "June";
else if ( m == 7 ) std::cout << "July";
else if ( m == 8 ) std::cout << "August";
else if ( m == 9 ) std::cout << "September";
else if ( m == 10 ) std::cout << "October";
else if ( m == 11 ) std::cout << "November";
else if ( m == 12 ) std::cout << "December";

std::cout << "\n S M T W T F S" << "\n";
std::cout << "____________________" << "\n";
}

void skip( unsigned int i ) {
while ( i > 0 ) {
std::cout << " ";
i--;
}
}

void printMonth( unsigned int numDays, unsigned int &weekDay ) {
skip( 3 * weekDay ); //3 is width of a calendar number
for ( unsigned int day = 1 ; day <= numDays ; day++ ) {
std::cout << std::setw(2) << day << " ";

if ( weekDay == 6 ) {
std::cout << "\n";
weekDay = 0;
}
else
weekDay++;
}
}

Answer 5

`Distance Calculator`
```
#include <iostream>
#include <cmath>
#include <string>

/*
This program takes 2 x,y coords and calculates the distance between them.
I wrote this cause I was getting tired of doing the math on paper for my
college algebra class :).
There is no input validation but I'll leave that up to anyone who wants to use it.
*/

void getValues(double &x, double &x1, double &y, double &y1);
void getDistance(const double x, const double x1, const double y, const double y1);

int main(void)
{

double x;
double x1;
double y;
double y1;
bool exit = false;
std::string exitletter;

while(!exit)
{
getValues(x,x1,y,y1);
getDistance(x,x1,y,y1);
std::cout<<"Another? (y or n)"<<std::endl;
std::cin>>exitletter;

if(exitletter == "n")
{
exit = true;
}

}

return 0;

}

void getValues(double &x, double &x1, double &y, double &y1)
{

std::cout<<"Enter x"<<std::endl;
std::cin>>x;
std::cout<<"Enter y"<<std::endl;
std::cin>>y;
std::cout<<"Enter x2"<<std::endl;
std::cin>>x1;
std::cout<<"Enter y2"<<std::endl;
std::cin>>y1;

}

void getDistance(const double x, const double x1, const double y, const double y1)
{

double distance;
double preSqrtValue;
preSqrtValue = ( pow( (x1 - x), 2) + pow( (y1 - y), 2) );
distance = sqrt( ( pow( (x1 - x), 2) + pow( (y1 - y), 2) ) );
std::cout<<"Before taking the square root "<<preSqrtValue<<std::endl;
std::cout<<"Distance equals "<<distance<<std::endl;

}

Answer 6

`Simple Calculator`
```
#include <iostream>

//A simple calculator using templates


template <class T>
T add(T a, T b)
{
T result;
result = a + b;
return result;
}

template <class T>
T subtract(T a, T b)
{
T result;
result = a - b;
return result;
}

template <class T>
T divide(T a, T b)
{
T result;
result = a / b;
return result;
}

template <class T>
T multiply(T a, T b)
{
T result;
result = a * b;
return result;
}

int main(void)
{

std::cout<<add<int>(10,20)<<std::endl;
std::cout<<subtract<float>(5.4,2.3)<<std::endl;
std::cout<<multiply<int>(4,5)<<std::endl;
std::cout<<divide<int>(9,3)<<std::endl;
std::cin.get();

return 0;
}

Answer 7

`Prime factor of a given number calculator`
```
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <ctype.h>

int main()
{
int x,div=2;


int i=0,j=0;
printf("Enter Number X : ");
scanf("%d",&x);
int num=x;
int *prime=(int *) malloc(x*sizeof(int));
printf("\n Allocated \n");
getch();
if (x==1 || x==0)
{ printf(" Number %d have no prime Factors",x);
*prime=0;
}
else
{ while(x>1)
{ if ((x%div)==0)
{ *(prime+i)=div;x=x/div;i++;printf("\n Prime Factor\n");

}
else
{ div++; }

}


}

printf("\n The Prime Factors for Number %d are :\n",num);

for(j=0;j<i;j++)

{ printf (" %d ",*(prime+j)); }

return(0);
}

Answer 8

```
\nyeh

Answer 9

```
<div style="text-align:center;width:400px;padding:1em 0;"> <h2><a style="text-decoration:none;" href="http://www.zeitverschiebung.net/en/city/5128581"><span style="color:gray;">Current local time in</span><br />New York City, United States</a></h2> <iframe src="https://www.zeitverschiebung.net/clock-widget-iframe-v2?language=en&timezone=America%2FNew_York" width="100%" height="150" frameborder="0" seamless></iframe> <small style="color:gray;">&copy; <a href="http://www.zeitverschiebung.net/en/" style="color: gray;">Time Difference</a></small> </div>

Answer 10

```
<!DOCTYPE html>
<html>
<head>
<title>Image Preview</title>
<script type="text/javascript" src="http://code.jquery.com/jquery.min.js"></script>
<style type="text/css">
* {
box-sizing: border-box;
position: relative;
-moz-box-sizing: border-box;
-webkit-box-sizing: border-box;
}
body {
background:#fff;
font-family:helvetica, arial, sans-serif;
color:#222;
font-size:16px;
}
form {
margin:3em;
}
form div.row {
width:400px;
padding:1em;
overflow:hidden;
background:#ededed;
border-radius:0.5em;
-moz-border-radius:0.5em;
-webkit-border-radius:0.5em;
}
form div.file-preview {
background:#ccc;
border:5px solid #fff;
box-shadow:0 0 4px rgba(0, 0, 0, 0.5);
-moz-box-shadow:0 0 4px rgba(0, 0, 0, 0.5);
-webkit-box-shadow:0 0 4px rgba(0, 0, 0, 0.5);
display:inline-block;
float:left;
margin-right:1em;
width:60px;
height:60px;
text-align:center;
}
form div.row label {
font-weight:bold;
display:block;
margin-bottom:0.25em;
}
</style>
</head>
<body>
<form action="blah" method="post" enctype="multipart/form-data">
<h1>Upload Image Preview</h1>
<p>Choose upload image.</p>
<div class="row">
<div class="file-preview"></div>
<label for="file-input">Select a File:</label>
<input id="file-input" type="file" name="file">
</div>
</form>

<script type="text/javascript">
$('input[type=file]').change(function(e) {
if(typeof FileReader == "undefined") return true;
var elem = $(this);
var files = e.target.files;
for (var i = 0, f; f = files; i++) { if (f.type.match('image.*')) { var reader = new FileReader(); reader.onload = (function(theFile) { return function(e) { var image = e.target.result; previewDiv = $('.file-preview', elem.parent()); bg_width = previewDiv.width() * 2; previewDiv.css({ "background-size":bg_width + "px, auto", "background-position":"50%, 50%", "background-image":"url("+image+")", }); }; })(f); reader.readAsDataURL(f); } } }); </script> </body> </html>