/* Name: Garrett Haldrup
lab8.c
Problem: Has programs that convert C° to F°, and 7 different patterns and calculating mean and sd of users grades. 
Certification of Authenticity:
I certify that this assignment is entirely my own work.
*/

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

void temperatureChart();
void apporxSqrt();
void patternA(int n);
void patternB(int n);
void patternC(int n);
void patternD(int n);
void patternE(int n);
void patternF(int n);
void patternG(int n);
void hwMean();
void hwStats();

int main() {

  temperatureChart();
  //apporxSqrt();
  patternA(8);
  patternB(8);
  patternC(8);
  patternD(8);
  patternE(8);
  patternF(8);
  patternG(8);
  //hwMean();
  hwStats();

  return 0;
}

void temperatureChart() {
  int c;
  float f;

  printf("This program will convert from °C to °F from 0 to 200 every 10°C\n");

  for (c = 0; c <= 200; c += 10) {
    f = (c * 1.8) + 32;

    printf("%d°C\t=   %.1f°F\n", c, f);
  }
}

void apporxSqrt() {
  int n, num;
  float guess;

  printf("This will estimate the square root of a number using newtons method\n");

  printf("Enter number: ");
  scanf("%d", &num);

  printf("Enter n: ");
  scanf("%d", &n);

  guess = num / 2.0;

  for (int i = 0; i < n; i++) {
    guess = (guess + (num / guess)) / 2.0;
  }

  printf("%.1f\n", guess);
}


void patternA(int n) {
  int num = 0;
  int sum = 0;

  printf("\nThis will show n values and sum of the pattern 2n\n");

  num += 2;
  sum += num;

  printf("%d", num);

  for (int i = 0; i < n; i++) {
    num += 2;
    sum += num;

    printf(" + %d", num);
  }
  printf(" = %d\n", sum);
}

void patternB(int n) {
  int num = 0;

  printf("\nThis will show the values for the pattern (-1)^n*(2 + 4n)\n");

  num = -6;
  printf("%d", num);
  for (int i = 1; i < n; i++) {
    num = abs(num) + 4;
    if (!(i % 2)) {
      num *= -1;
    }
    printf(", %d", num);
  }
  printf("\n");
}

void patternC(int n) {
  printf("\nThis will show the pattern of 4 * ((n + 1) %% 2)\n");
  int num = 0;
  printf("%d", num);
  for (int i = 1; i < n; i++) {
    num = 4 * (i % 2);
    printf(", %d", num);
  }
  printf("\n");
}

void patternD(int n) {
  int num = 1;
  int sum = 0;

  printf("\nThis will show the pattern and sum of 1 + 2n * ((n %% 2) - 1)\n");

  sum += num;

  printf("%d", num);

  for (int i = 1; i < n; i++) {
    num = abs(num + (2 * ((i) % 2))) * pow(-1, i);
    if (i % 2) {
      printf(" - %d", abs(num));
    } else {
      printf(" + %d", num);
    }

    sum += num;

  }
  printf(" = %d\n", sum);
}

void patternE(int n) {
  printf("\nThis will show the pattern of 3^n\n");
  int num = 3;
  printf("%d", num);
  for (int i = 1; i < n; i++) {
    num = pow(3, i + 1);
    printf(", %d", num);
  }
  printf("\n");
}

void patternF(int n) {
  int top = 1;
  int bot = 4;

  printf("\nThis will show the pattern and product of (3^n-1)/2+2n\n");
  float product = 1;

  product *= (float)top / (float)bot;
  printf("(%d/%d)", top, bot);

  for (int i = 1; i < n; i++) {
    top = pow(3, i);
    bot += 2;
    printf(" * (%d/%d)", top, bot);
      
    product *= (float)top / (float)bot;
  }
  printf(" = %.1f\n", product);
}


void patternG(int n) {
  int num = 9;
  int sum = 9;

  printf("\nThis will show the pattern and sum of (2 + n)^2\n");

  printf("%d", num);

  for (int i = 1; i < n; i++) {
    num = pow(i + 3, 2);
    sum += num;

    printf(" + %d", num);
  }
  printf(" = %d\n", sum);
}

void hwMean() {
  int n;
  float grades[20];
  float mean;
  float sum = 0;

  printf("\nThe program will show the mean of your inputed grades\n");

  printf("Enter the number of assignments: ");
  scanf("%d", &n);

  for (int i = 0; i < n; i++) {
    printf("Enter your grade on HW%d: ", i + 1);
    scanf("%f", &grades[i]);
    sum += grades[i];
  }
  mean = sum / n;
  printf("Your overall average is: %.1f\n", mean);


}

void hwStats() {
  int n = 1;
  float grades[20];
  float mean;
  float sum = 0;
  float sd;
  
  printf("\nThe program will show the mean, and standard deviation of your inputed grades\n");

  while(1) {
    printf("Enter the number of assignments: ");
    scanf("%d", &n);
    if (n <= 20 && n > 0) {
      break;
    } else {
      printf("Must be less than or equal to 20!\n");
    }
  }
  

  for (int i = 0; i < n; i++) {
    printf("Enter your grade on HW%d: ", i + 1);
    scanf("%f", &grades[i]);
    sum += grades[i];
  }
  mean = sum / n;
  printf("Your overall average is: %.1f\n", mean);


  sum = 0;
  for (int i = 0; i < n; i++) {
    sum += pow(grades[i] - mean, 2);
  }
  
  sd = sqrt((1.0/n) * sum);

  printf("The standard deviation(σ) is: %.1f\n", sd);


}