1.13

The C Programming Language/1.13.c

@@ -0,0 +1,32 @@
+#include <stdio.h>
+
+main()
+{
+	int c, i, nwhite, nother;
+	int ndigit[10];
+
+	nwhite = nother = 0;
+	for (i = 0; i < 10; ++i)
+		ndigit[i] = 0;
+
+	while ((c = getchar()) != EOF)
+		if (c >= '0' && c <= '9')
+			++ndigit[c-'0'];
+		else if (c == ' ' || c == '\t')
+			++nwhite;
+		else if (c == '\n')
+		{
+			++nwhite;
+			printf("digits = ");
+			for (i = 0; i < 10; ++i)
+				printf(" %d", ndigit[i]);
+			printf(", white space = %d, other = %d\n", nwhite, nother);
+		}
+		else
+			++nother;
+
+	printf("digits = ");
+	for (i = 0; i < 10; ++i)
+		printf(" %d", ndigit[i]);
+	printf(", white space = %d, other = %d\n", nwhite, nother);
+}

The Last Algorithms Course You'll Need/1. Big O Time Complexity.md

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+Important concepts
+
+Big O is a way to categorize your algorithms time or memory requirements based on input.
+
+-    Growth is with respect to the input
+-    Constants are dropped
+-    Worst case is usually the way we measure
+

The Last Algorithms Course You'll Need/2. Arrays Data Structure.md

@@ -0,0 +1,17 @@
+array [0][]
+
+a + width * offset
+
+contigious memory
+
+```
+int a[3];
+
+[ jakdf ] [ adsfa ] [ vdsfv ]
+
+a[1] = 4;
+
+[ jakdf ] [ 4     ] [ vdsfv ]
+```
+
+O(1) operations, do not grow by input, we know all the positions and variables, so we just multiply

The Last Algorithms Course You'll Need/3. Linear Search.c

@@ -0,0 +1,33 @@
+#include <stdio.h>
+
+#define SIZE 55
+
+// Search complexity is O(n)
+// bc growths in respect to input, if array is 999
+// in the worst case the search will take 999 iterations over the loop
+// if array is 4, the worst case will take 4 loops
+
+int linear_search(int array[], int size, int value)
+{
+	for (int i = 0; i < size; ++i)
+		if (array[i] == value)
+			return 1;
+
+	return 0;
+}
+
+int main()
+{
+	int array[SIZE];
+	for (int i = 0; i < SIZE; ++i)
+		array[i] = 0;
+
+	array[3] = 45;
+	int value = 45;
+
+	int is_found = linear_search(array, SIZE, value);
+	printf("1 if found: %d\n", is_found);
+	
+	is_found = linear_search(array, SIZE, 99);
+	printf("1 if found: %d\n", is_found);
+}

The Last Algorithms Course You'll Need/4. Binary Search.c

@@ -0,0 +1,44 @@
+#include "stdio.h"
+
+#define SIZE 4096
+
+int binary_search(int array[], int size, int offset, int value)
+{
+	int pivot = size / 2;
+	int current_value = array[offset + pivot];
+			printf("At %d\n", offset + pivot);
+
+	if (current_value == value)
+	{
+		return 1;
+	}
+	
+
+	if (pivot > 0)
+	{
+		if (current_value > value)
+			return binary_search(array, pivot, offset, value);
+		else
+			return binary_search(array, pivot, offset + pivot, value);
+	}
+	
+	return 0;
+}
+
+int main()
+{
+	int array[SIZE];
+	for (int i = 0; i < SIZE; ++i)
+		array[i] = i;
+
+	printf("1 if found: %d\n", binary_search(array, SIZE, 0, 5243));
+	printf("1 if found: %d\n", binary_search(array, SIZE, 0, 1));
+	printf("1 if found: %d\n", binary_search(array, SIZE, 0, 1044));
+//	for (int i = 0; i < SIZE; ++i)
+//		if (!binary_search(array, SIZE, 0, i))
+//			printf("YOU FUCKED UP!!! at index %d\n", i);
+	printf("1 if found: %d\n", binary_search(array, SIZE, 0, SIZE));
+	array[14] = 13;
+	printf("1 if found: %d\n", binary_search(array, SIZE, 0, 14));
+
+}