2. (Car-Pool Savings Calculator) Research several car-pooling websites. Create an application that calculates your daily driving cost, so that you can estimate how much money could be saved by carpooling, which also has other advantages such as reducing carbon emissions and reducing traffic congestion. The application should input the following information and display the user’s cost per day of driving to work: a) Total miles driven per day. b) Cost per gallon of gasoline. c) Average miles per gallon. d) Parking fees per day. e) Tolls per day.

#include <linux/limits.h>

char current_path[PATH_MAX];

#include "SevSeg.h"
SevSeg sevseg;

int LEDRa = 33;
int LEDGa = 32;

int LEDRb = 23;
int LEDGb = 22;

int LEDRc = 50;
int LEDGc = 51;

int LEDRd = 42;
int LEDGd = 43;

int IRa1 = 44;
int IRa2 = 52;

int IRb1 = 49;
int IRb2 = 48;

int IRc1 = 35;
int IRc2 = 37;

int IRd1 = 47;
int IRd2 = 46;

int RoadATraffic[] = {0, 0};
int RoadBTraffic[] = {0, 0};
int RoadCTraffic[] = {0, 0};
int RoadDTraffic[] = {0, 0};

char jam[] = {'a', 'b', 'c', 'd', 'a', 'b', 'c', 'd', 'a', 'b', 'c', 'd', 'a', 'b', 'c', 'd'};

void setup() {
  pinMode (LEDRa, OUTPUT);
  pinMode (LEDGa, OUTPUT);

  pinMode (LEDRb, OUTPUT);
  pinMode (LEDGb, OUTPUT);

  pinMode (LEDRc, OUTPUT);
  pinMode (LEDGc, OUTPUT);

  pinMode (LEDRd, OUTPUT);
  pinMode (LEDGd, OUTPUT);

  pinMode (IRa1, INPUT);
  pinMode (IRa2, INPUT);

  pinMode (IRb1, INPUT);
  pinMode (IRb2, INPUT);

  pinMode (IRc1, INPUT);
  pinMode (IRc2, INPUT);

  pinMode (IRd1, INPUT);
  pinMode (IRd2, INPUT);

  byte numDigits = 2;
  byte digitPins[] = {11, 10};
  byte segmentPins[] = {9, 8, 6, 3, 4, 7, 2, 5};
  bool resistorsOnSegments = true;

  byte hardwareConfig = COMMON_CATHODE;
  sevseg.begin(hardwareConfig, numDigits, digitPins, segmentPins, resistorsOnSegments);
  sevseg.setBrightness(90);

  Serial.begin(9600); // open the serial port at 9600 bps:
}

static int counter = 5;
int jam_ind = 0;
int current_route = 0;

void loop() {
    //display();
    RoadATraffic[0] = (digitalRead (IRa1) != 1) ? ( 1 ) : ( 0 );
    RoadATraffic[1] = (digitalRead (IRa2) != 1) ? ( 1 ) : ( 0 );

    RoadBTraffic[0] = (digitalRead (IRb1) != 1) ? ( 1 ) : ( 0 );
    RoadBTraffic[1] = (digitalRead (IRb2) != 1) ? ( 1 ) : ( 0 );

    RoadCTraffic[0] = (digitalRead (IRc1) != 1) ? ( 1 ) : ( 0 );
    RoadCTraffic[1] = (digitalRead (IRc2) != 1) ? ( 1 ) : ( 0 );

    RoadDTraffic[0] = (digitalRead (IRd1) != 1) ? ( 1 ) : ( 0 );
    RoadDTraffic[1] = (digitalRead (IRd2) != 1) ? ( 1 ) : ( 0 );

    int sum1 = RoadATraffic[0] + RoadATraffic[1];
    int sum2 = RoadBTraffic[0] + RoadBTraffic[1];
    int sum3 = RoadCTraffic[0] + RoadCTraffic[1];
    int sum4 = RoadDTraffic[0] + RoadDTraffic[1];

    Serial.print(current_route);
    Serial.print('\n');
    Serial.print(jam_ind);
    Serial.print('\n');
    Serial.print('\n');

    change_route(jam[current_route]);
    display();
      
    if (sum1 >= sum2 && sum1 >= sum3 && sum1 >= sum4) {     // Road A Jam
      if (jam[current_route] == 'a' && counter == 1) {
        increase_jam_ind();
        jam[jam_ind] = 'a';
      } else if (jam[current_route] != 'a' && jam[jam_ind] != 'a') {
        increase_jam_ind();
        jam[jam_ind] = 'a';
      }
    }

    if (sum2 >= sum1 && sum2 >= sum3 && sum2 >= sum4) { // Road B Jam
      if (jam[current_route] == 'b' && counter == 1) {
        increase_jam_ind();
        jam[jam_ind] = 'b';
      } else if (jam[current_route] != 'b' && jam[jam_ind] != 'b') {
        increase_jam_ind();
        jam[jam_ind] = 'b';
      }
    }
    
    if (sum3 >= sum1 && sum3 >= sum2 && sum3 >= sum4) { // Road C Jam
      if (jam[current_route] == 'c' && counter == 1) {
        increase_jam_ind();
        jam[jam_ind] = 'c';
      } else if (jam[current_route] != 'c' && jam[jam_ind] != 'c') {
        increase_jam_ind();
        jam[jam_ind] = 'c';
      }
    }
      
    if (sum4 >= sum1 && sum4 >= sum2 && sum4 >= sum3) { // Road D Jam
      if (jam[current_route] == 'd' && counter == 1) {
        increase_jam_ind();
        jam[jam_ind] = 'd';
      } else if (jam[current_route] != 'd' && jam[jam_ind] != 'd') {
        increase_jam_ind();
        jam[jam_ind] = 'd';
      }
    }  
}

void display() {
  for (int h = 1; h<10000; h++){
    sevseg.setNumber(counter);
    sevseg.refreshDisplay();  
  }
  if (counter <= 0) {
    counter = 5;
    current_route++;
  }

  if (current_route > 15) { 
    current_route = 0;
  }
  
  counter--;
}

void change_route(char route) {
  switch (route) {
    case 'a':
      digitalWrite(LEDGa, HIGH);
      digitalWrite(LEDRa, LOW);
    
      digitalWrite(LEDGb, LOW);
      digitalWrite(LEDRb, HIGH);
    
      digitalWrite(LEDGc, LOW);
      digitalWrite(LEDRc, HIGH);
    
      digitalWrite(LEDGd, LOW);
      digitalWrite(LEDRd, HIGH);
      break;

    case 'b':
      digitalWrite(LEDGa, LOW);
      digitalWrite(LEDRa, HIGH);
    
      digitalWrite(LEDGb, HIGH);
      digitalWrite(LEDRb, LOW);
    
      digitalWrite(LEDGc, LOW);
      digitalWrite(LEDRc, HIGH);
    
      digitalWrite(LEDGd, LOW);
      digitalWrite(LEDRd, HIGH);
      break;

    case 'c':
      digitalWrite(LEDGa, LOW);
      digitalWrite(LEDRa, HIGH);
    
      digitalWrite(LEDGb, LOW);
      digitalWrite(LEDRb, HIGH);
    
      digitalWrite(LEDGc, HIGH);
      digitalWrite(LEDRc, LOW);
    
      digitalWrite(LEDGd, LOW);
      digitalWrite(LEDRd, HIGH);
      break;

    case 'd':
      digitalWrite(LEDGa, LOW);
      digitalWrite(LEDRa, HIGH);
    
      digitalWrite(LEDGb, LOW);
      digitalWrite(LEDRb, HIGH);
    
      digitalWrite(LEDGc, LOW);
      digitalWrite(LEDRc, HIGH);
    
      digitalWrite(LEDGd, HIGH);
      digitalWrite(LEDRd, LOW);
      break;
  }
}

void increase_jam_ind() {
  jam_ind++;
  if (jam_ind > 15) {
    jam_ind = 0;
  }
}

#include <stdio.h>

int main(){
  char str[20];
  
  fgets(str, 20, stdin); // read from stdin
  puts(str); // print read content out to stdout
  
  // open the file
  FILE *f = fopen("file.txt" , "r"); 
  
  // if there was an error
  if(f == NULL){
    perror("Error opening file"); // print error
    return(-1); 
  }
  // if there was no error
  else{ 
    fgets(str, 20, f); // read from file
    puts(str); // print read content out to stdout
  }
  
  fclose(f); // close file
  
  return(0);
}

sdk_path="/Library/Developer/CommandLineTools/SDKs"

class Wrapper
{
 private:
  CLib *lib;

 public:
  Wrapper() { lib = lib_init(); } // Lib initialisieren
  ~Wrapper() { lib_cleanup(&init); } // Lib freigeben

  std::string DoSomething() 
  { 
    char *cstr = lib_get_str(); // String anfordern (malloc!)

    std::string s = str;  // in std::string kopieren

    lib_free_str(cstr); // String freigeben (free)

    return s; // std::string zurückgeben. Alles easy.
  }
};

class int_ptr_wrapper
{
public:
    int_ptr_wrapper(int value = 0) :
    mInt(new int(value))
    {}

    // note! needs copy-constructor and copy-assignment operator!

    ~int_ptr_wrapper()
    {
        delete mInt;
    }

private:
    int* mInt;
};

#include<stdio.h>
typedef struct student{
    int roll;
    char name[100];
    int marks[3];
}st;
void takeinput(st candidate[]){
     for(int i=0;i<5;i++){
        printf("\nFor student %d\n",i+1);
        printf("Enter the following details\n");
        printf("roll:");
        scanf("%d",&candidate[i].roll);
        printf("name:");
        scanf("%s",candidate[i].name);
        for(int j=0;j<3;j++){
            printf("marks in subject %d:",j+1);
            scanf("%d",&candidate[i].marks[j]);
        }
     }
}
void printinput(st candidate[]){
    printf("The details of all the students are as follows\n");
    for(int i=0;i<5;i++){
        printf("\nroll no:%d\nname:%s\n",candidate[i].roll,candidate[i].name);
        for(int j=0;j<3;j++){
            printf("marks in subject %d:%d\n",j+1,candidate[i].marks[j]);
        }
    }
}
void average_st_mks(st candidate[]){
    printf("Enter the serial number(1-5) of the student whose average marks to be known\n");
    int no;
    scanf("%d",&no);
    int sum=0;
    for(int i=0;i<3;i++) sum+=candidate[no-1].marks[i];
    float avg=(float)sum/3;
    printf("The average marks candidate bearing roll:%d is %.2f\n",candidate[no-1].roll,avg);
}
void average_subj_mks(st candidates[]){
    printf("Enter the serial number(1-3) of the subject whose average is to be known\n");
    int subject_number;
    scanf("%d",&subject_number);
    int sum=0;
    for(int i=0;i<5;i++){
        sum+=candidates[i].marks[subject_number-1];
    }
    float avg=(float)sum/5;
    printf("The average score of students in subject no:%d is %.2f\n",subject_number,avg);
}
void swap(st *candidate){
    printf("Enter the serial number(1-5) of student whose subject marks are to be swapped\n");
    int i;
    scanf("%d",&i);
    printf("Enter the serial number(1-3) of two subjects whose marks to be swapped\n");
    int a,b;
    scanf("%d%d",&a,&b);
    int temp=candidate[i-1].marks[a-1];
    candidate[i-1].marks[a-1]=candidate[i-1].marks[b-1];
    candidate[i-1].marks[b-1]=temp;
}
void print_mks_student(st candidate[]){
    printf("Enter the serial number(1-5) of the student you want to print marks\n");
    int n;
    scanf("%d",&n);
    for(int i=0;i<3;i++){
        printf("subject %d: %d mks\n",i+1,candidate[n-1].marks[i]);
    }
}
void upp_to_low(st candidate[]){
    printf("Enter the serial number(1-5) of student you want to convert name to lowercase\n");
    int n;
    scanf("%d",&n);
    int i=0;
    do{
        char ch=candidate[n-1].name[i];
        if(ch>=65 && ch<=90) candidate[n-1].name[i]=ch+32;
        i++;
    }while(candidate[n-1].name[i]!='\0');
    printf("student name changed to %s\n",candidate[n-1].name);
}
int main(){
    st candidate[5];
    int flag=1;
    char choice;
    do{
        printf("\nEnter the choice from the menu as per mentioned in the question paper\n");
        printf("The choice should be between a-g(lowercase)\nEnter any other character to stop the program\n");
        scanf(" %c",&choice);
        switch(choice){
        case 'a':takeinput(candidate);
        break;
        case 'b':printinput(candidate); 
        break;
        case 'c':average_st_mks(candidate);
        break;
        case 'd':average_subj_mks(candidate);
        break;
        case 'e':swap(candidate);
        break;
        case 'f':print_mks_student(candidate);
        break;
        case 'g':upp_to_low(candidate);
        break;
        default: flag=0;
        }
    }while(flag==1);
    return 0;
}

#include<stdio.h>
#define take(n) scanf("%d",&n);
#define rep(i,a,b) for(int i=a;i<b;i++)
void add_10(int n){
    printf("Enter a number\n");
    int x;
    take(x);
    printf("%d+%d=%d\n",n,x,n+x);
}
void multiply_10(int n){
    printf("Enter a number\n");
    int x;
    take(x);
    printf("%d*%d=%d\n",n,x,n*x);
}

int main()
{
    int n=10;
    char choice;
    int flag=0;
    do{
        printf("Enter your choice either a or b, any other to exit\n");
        scanf("%c",&choice);
        switch(choice){
            case 'A':
            case 'a': add_10(n);
            break;
            case 'B':
            case 'b': multiply_10(n);
            break;
            default: flag=1;
        }
    }while(flag==0);
return 0;
}

#include <stdio.h>
int main()
{
	int lenght,bredth;
	int end;
	printf("what is the lenght of the rectangle \n");
	scanf("%d",&lenght);
	printf("what is the bredth of rectangle \n");
    scanf("%d",&bredth);
    printf("area of rectangle = %d \n",lenght*bredth);
    printf("Programe By Aaryan \n");
    printf("press any key to proseed");
    scanf("%d",&end);
	return 0;
} 

j = 0;
S = range(256)
for i in range(256):
    j = (j + S[i] + K[i%n]) % 256
    S[i], S[j] = S[j], S[i]

i = 0
j = 0
for b in range(m):
    i = (i + 1) % 256
    j = (j + S[i]) % 256
    S[i], S[j] = S[j], S[i]
    KS[b] = S[(S[i] + S[j]) % 256]

#define R(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
void salsa20_word_specification(uint32 out[16],uint32 in[16])
{
    int i;
    uint32 x[16];
    for (i = 0;i < 16;++i) x[i] = in[i];
    for (i = 20;i > 0;i -= 2) {
        x[ 4] ^= R(x[ 0]+x[12], 7);  x[ 8] ^= R(x[ 4]+x[ 0], 9);
        x[12] ^= R(x[ 8]+x[ 4],13);  x[ 0] ^= R(x[12]+x[ 8],18);
        x[ 9] ^= R(x[ 5]+x[ 1], 7);  x[13] ^= R(x[ 9]+x[ 5], 9);
        x[ 1] ^= R(x[13]+x[ 9],13);  x[ 5] ^= R(x[ 1]+x[13],18);
        x[14] ^= R(x[10]+x[ 6], 7);  x[ 2] ^= R(x[14]+x[10], 9);
        x[ 6] ^= R(x[ 2]+x[14],13);  x[10] ^= R(x[ 6]+x[ 2],18);
        x[ 3] ^= R(x[15]+x[11], 7);  x[ 7] ^= R(x[ 3]+x[15], 9);
        x[11] ^= R(x[ 7]+x[ 3],13);  x[15] ^= R(x[11]+x[ 7],18);
        x[ 1] ^= R(x[ 0]+x[ 3], 7);  x[ 2] ^= R(x[ 1]+x[ 0], 9);
        x[ 3] ^= R(x[ 2]+x[ 1],13);  x[ 0] ^= R(x[ 3]+x[ 2],18);
        x[ 6] ^= R(x[ 5]+x[ 4], 7);  x[ 7] ^= R(x[ 6]+x[ 5], 9);
        x[ 4] ^= R(x[ 7]+x[ 6],13);  x[ 5] ^= R(x[ 4]+x[ 7],18);
        x[11] ^= R(x[10]+x[ 9], 7);  x[ 8] ^= R(x[11]+x[10], 9);
        x[ 9] ^= R(x[ 8]+x[11],13);  x[10] ^= R(x[ 9]+x[ 8],18);
        x[12] ^= R(x[15]+x[14], 7);  x[13] ^= R(x[12]+x[15], 9);
        x[14] ^= R(x[13]+x[12],13);  x[15] ^= R(x[14]+x[13],18);
    }
    for (i = 0;i < 16;++i) out[i] = x[i] + in[i];
}

#include <stdio.h>
int main () {
    char username[8];
    int allow = 0;
    printf external link("Enter your username, please: ");
    gets(username);
    if (grantAccess(username)) {
        allow = 1;
    }
    if (allow != 0) {
        privilegedAction();
    }
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
 
#define MY_TMP_FILE "/tmp/file.tmp"
 
 
int main(int argc, char* argv[])
{
    FILE * f;
    if (!access(MY_TMP_FILE, F_OK)) {
        printf external link("File exists!\n");
        return EXIT_FAILURE;
    }
    tmpFile = fopen(MY_TMP_FILE, "w");
 
    if (tmpFile == NULL) {
        return EXIT_FAILURE;
    }
 
    fputs("Some text...\n", tmpFile);
 
    fclose(tmpFile);
 
    return EXIT_SUCCESS;
}