Question

For each question, you are required to draw a flowchart diagram and a C++ program. For flow charts you are required to use a Computer Aided Software Engineering (CASE) tool for example Dia (Download from http://diainstaller.de/).

a. Write a program that prints the first 107 prime numbers.

b. Write a program that determines whether a number given by the user is a leap year or not.

Please write a program in c++.. Thank you and add the comments for the lines

Answer 1

a)

#include<iostream>

using namespace std;

//method to check if number is prime

bool isPrime(int n) {

//loop to run from 2 to half of n

for(int i = 2; i <= n / 2; ++i)

{

//if number is divisible by any number completely return false

if(n % i == 0)

{

return false;

}

}

//else return true

return true;

}

//method to run the program

int main() {

int countPrimes = 1;//counter holding number of primes printed

int prime = 3;

//printing first prime number

cout<<countPrimes<<": "<<2<<endl;

//printing first 107 prime numbers starting from 3

while(countPrimes < 107) {

//checking if number is prime

if(isPrime(prime)) {

//if its prime, then printing the number and increment the counter.

cout<<(++countPrimes)<<": "<<prime<<endl;

}

//increment the number.

prime++;

}

return 0;

}

Output

1: 2
2: 3
3: 5
4: 7
5: 11
6: 13
7: 17
8: 19
9: 23
10: 29
11: 31
12: 37
13: 41
14: 43
15: 47
16: 53
17: 59
18: 61
19: 67
20: 71
21: 73
22: 79
23: 83
24: 89
25: 97
26: 101
27: 103
28: 107
29: 109
30: 113
31: 127
32: 131
33: 137
34: 139
35: 149
36: 151
37: 157
38: 163
39: 167
40: 173
41: 179
42: 181
43: 191
44: 193
45: 197
46: 199
47: 211
48: 223
49: 227
50: 229
51: 233
52: 239
53: 241
54: 251
55: 257
56: 263
57: 269
58: 271
59: 277
60: 281
61: 283
62: 293
63: 307
64: 311
65: 313
66: 317
67: 331
68: 337
69: 347
70: 349
71: 353
72: 359
73: 367
74: 373
75: 379
76: 383
77: 389
78: 397
79: 401
80: 409
81: 419
82: 421
83: 431
84: 433
85: 439
86: 443
87: 449
88: 457
89: 461
90: 463
91: 467
92: 479
93: 487
94: 491
95: 499
96: 503
97: 509
98: 521
99: 523
100: 541
101: 547
102: 557
103: 563
104: 569
105: 571
106: 577
107: 587

b)

#include <iostream>

using namespace std;

//method to run the program

int main()

{

int year;

//getting number from user

cout << "Enter a year: ";

cin >> year;

// checking if number is leap year

if (year % 4 == 0)

{

if (year % 100 == 0)

{ //if satisfies all conditions, then its leap year

if (year % 400 == 0)

cout << year << " is a leap year.";

else

cout << year << " is not a leap year.";

}//each else means its not a leap year

else

cout << year << " is a leap year.";

}

else

cout << year << " is not a leap year.";

return 0;

}

Output

Enter a year: 1992
1992 is a leap year.