Init repository

.gitignore

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+a.out

comprun.sh

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+#!/bin/sh
+
+gcc hello.c
+./a.out

hello.c

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+#include <stdio.h>
+
+float farenheitToCelsius(float farenheit) {
+  return (farenheit - 32.0) / 1.8;
+}
+
+float celsiusToFarenheit(float celsius) {
+  return (celsius * 1.8) + 32.0;
+}
+
+int sizeofStr(char in[]) {
+  int i = 0;
+  for (i = 0; in[i] != '\0'; ++i)
+    ;
+  return i;
+}
+
+void printStrArray(char in[]) {
+  int i;
+  printf("{ ");
+  for (i = 0; i < sizeofStr(in); ++i) {
+    printf("%c", in[i]);
+    if (i == sizeofStr(in) - 1) {
+      printf(" }\n");
+    } else {
+      printf(", ");
+    }
+  }
+}
+
+void printIntArray(int in[], int inLength) {
+  int i;
+  printf("{ ");
+  for (i = 0; i < inLength; ++i) {
+    printf("%d", in[i]);
+    if (i == inLength - 1) {
+      printf(" }\n");
+    } else {
+      printf(", ");
+    }
+  }
+}
+
+int checkIntArraySorted(int in[], int inLength) {
+  int i = 0;
+  while(i < inLength - 1) {
+    if (in[i] > in[i + 1])
+      return 0;
+    ++i;
+  }
+  
+  return 1;
+}
+
+void swapInt(int *x, int *y) {
+  int temp = *x;
+  *x = *y;
+  *y = temp;
+}
+
+/* Count the number of digits an integer has */
+unsigned long long intDigitCount(unsigned long long in) {
+  unsigned long long largestDigit;
+  int digitCount = 0;
+  for (largestDigit = 1; in / largestDigit != 0; largestDigit *= 10)
+    ++digitCount;
+  return digitCount;
+}
+
+/* Expand an integer into an integer whose first unit is 1 followed by a leading trail of 0's*/
+unsigned long long intDigitExpand(unsigned long long in) {
+  int expandedDigit;
+  for (expandedDigit = 1; in != 1; --in)
+    expandedDigit *= 10;
+  return expandedDigit; 
+}
+
+/* Convert an integer array into a combined integer */
+int intArrayToInt(int in[], int inLength) {
+  int i;
+  int out = 0;
+  int currentDigit = inLength;
+  for (i = 1; i <= inLength; ++i) {
+    out += in[i - 1] * intDigitExpand(currentDigit);
+    --currentDigit;
+  }
+  return out;
+}
+
+/* Split an integer into an integer array */
+void intToIntArray(int in, int out[]) {
+  int i;
+  int j = 0;
+  int currentDigit;
+  for(i = intDigitCount(in); i >= 1; --i) {
+    out[j] = in / intDigitExpand(i);
+    in -= intDigitExpand(i) * out[j];
+    ++j;
+  }
+}
+
+/* Pseudo Random Number Generator using the Middle-square method */
+int randIntMiddleSquare(unsigned long long *seed, int iteration) {
+  int i;
+  int oldSeedLength = intDigitCount(*seed);
+  for (i = 0; i < iteration; ++i) {
+    unsigned long long seedSquared = *seed * *seed;
+    unsigned long long seedSquaredLength = intDigitCount(seedSquared);
+    printf("Seed squared: %d\n", seedSquared);
+    printf("Seed squared length: %d\n", seedSquaredLength);
+    int seedSquaredArray[seedSquaredLength]; 
+    int middleStart = (seedSquaredLength - oldSeedLength) / 2;
+    printf("Middle start: %d\n", middleStart);
+    int newSeedArray[oldSeedLength];
+    int j;
+    intToIntArray(seedSquared, seedSquaredArray);
+    for (int j = 0; j < oldSeedLength; ++j) {
+      newSeedArray[j] = seedSquaredArray[middleStart];
+      ++middleStart;
+    }
+    printIntArray(newSeedArray, sizeof(newSeedArray) / sizeof(int));
+    unsigned long long newSeed = intArrayToInt(newSeedArray, sizeof(newSeedArray) / sizeof(int));
+    int newSeedLength = intDigitCount(newSeed);
+    /* If the result has fewer than 2n digits, leading zeroes are added to compensate */
+    if (newSeedLength < oldSeedLength)
+      newSeed *= intDigitExpand(oldSeedLength - newSeedLength) * 10; 
+    *seed = newSeed;
+  }
+
+  return *seed;
+}
+
+int randIntMiddleSquareRange(int start, int end, unsigned long long *seed) {
+
+  int endLength = intDigitCount(end);
+  if (endLength > intDigitCount(*seed))
+    return -1;
+  
+  unsigned long long randomNumber = randIntMiddleSquare(seed, 1);
+  printf("The random number: %d\n", randomNumber);
+  int randomNumberLength = intDigitCount(randomNumber);
+  int randomNumberArray[randomNumberLength];
+  int truncatedNumber;
+  int truncatedNumberArray[endLength];
+  int middleStart = (randomNumberLength - endLength) / 2;
+  intToIntArray(randomNumber, randomNumberArray);
+  for (int j = 0; j < endLength; ++j) {
+    truncatedNumberArray[j] = randomNumberArray[middleStart];
+    ++middleStart;
+  }
+  truncatedNumber = intArrayToInt(truncatedNumberArray, sizeof(truncatedNumberArray) / sizeof(int));
+  
+  if (truncatedNumber <= end && truncatedNumber >= start)
+    return truncatedNumber;
+  else
+    randIntMiddleSquareRange(start, end, seed);
+}
+
+int main() {
+  int unsortedArray[] = { 1, 5, 2, 1, 4, 8, 3, 2, 6, 7 };
+  int sortedArray[] = { 1, 2, 4, 8, 9, 9, 9 };
+
+  printf("Unsorted Array : ");
+  printIntArray(unsortedArray, sizeof(unsortedArray) / sizeof(int));
+  printf("Unsorted Array Sorted?: %d\n", checkIntArraySorted(unsortedArray, sizeof(unsortedArray) / sizeof(int)));
+  printf("Sorted Array : ");
+  printIntArray(sortedArray, sizeof(sortedArray) / sizeof(int));
+  printf("Sorted Array Sorted?: %d\n", checkIntArraySorted(sortedArray, sizeof(sortedArray) / sizeof(int)));
+
+  int number = 3372; 
+  int intArray[4];
+
+  intToIntArray(number, intArray);
+  printIntArray(intArray, sizeof(intArray) / sizeof(int));
+
+  printf("Back to int %d\n", intArrayToInt(intArray, sizeof(intArray) / sizeof(int)));
+
+  unsigned long long seed = 3791;
+  printf("Squared: %d\n", seed * seed);
+  int iteration = 1;
+  printf("Starting random number %d\n", seed);
+  printf("Random number is %d after iteration %d\n", randIntMiddleSquare(&seed, iteration), iteration);
+
+  printf("Random: %d\n", randIntMiddleSquareRange(1, 10, &seed));
+
+}