first commit

Author: vvvvvvvector

.gitignore

@@ -0,0 +1,9 @@
+# Ignore Everything
+*
+
+# But not .cpp
+!*.cpp
+# Or directories
+!*/
+!.gitignore
+!README.md

2DArray/main.cpp

@@ -0,0 +1,56 @@
+#include <iostream>
+#include <ctime>
+
+int main()
+{
+    srand(time(NULL));
+
+    int row;
+    int col;
+
+    std::cin >> row >> col;
+
+    int **arr = new int *[row];
+    for (int i = 0; i < row; i++)
+    {
+        arr[i] = new int[col];
+    }
+
+    for (int i = 0; i < row; i++)
+    {
+        for (int j = 0; j < col; j++)
+        {
+            arr[i][j] = rand() % 100 - 50;
+            //std::cin >> arr[i][j];
+        }
+    }
+
+    for (int i = 0; i < row; i++)
+    {
+        for (int j = 0; j < col; j++)
+        {
+            //std::cout << arr[i][j] << " ";
+            printf("%d ", arr[i][j]);
+        }
+        std::cout << std::endl;
+    }
+
+    for (int i = 0; i < row; i++)
+    {
+        delete[] arr[i];
+    }
+
+    delete[] arr;
+
+    for (int i = 0; i < row; i++)
+    {
+        for (int j = 0; j < col; j++)
+        {
+            std::cout << arr[i][j] << " ";
+            //printf("%d ", arr[i][j]);
+        }
+        std::cout << std::endl;
+    }
+
+    return 0;
+}

AverageSumArray/main.cpp

@@ -0,0 +1,59 @@
+#include <iostream>
+#include <ctime>
+
+int main()
+{
+    srand(time(NULL));
+
+    const int row = 3;
+    const int col = 3;
+
+    int arr[row][col];
+    double average[row] = {0.0};
+
+    for (int x = 0; x < row; x++)
+    {
+        for (int y = 0; y < col; y++)
+        {
+            arr[x][y] = rand() % 21;
+        }
+    }
+
+    for (int x = 0; x < row; x++)
+    {
+        for (int y = 0; y < col; y++)
+        {
+            std::cout << arr[x][y] << " ";
+        }
+        std::cout << std::endl;
+    }
+
+    for (int x = 0; x < row; x++)
+    {
+        for (int y = 0; y < col; y++)
+        {
+            average[x] += arr[x][y];
+        }
+        average[x] = average[x] / (double)row;
+    }
+
+    int max = average[0];
+    int index;
+    for (int i = 0; i < row; i++)
+    {
+        if (average[i] > max)
+        {
+            max = average[i];
+            index = i;
+        }
+    }
+
+    for (int i = 0; i < row; i++)
+    {
+        std::cout << average[i] << " ";
+    }
+    
+    std::cout << std::endl << "Index = " << index;
+
+    return 0;
+}

Bin2Dec/main.cpp

@@ -0,0 +1,23 @@
+#include <iostream>
+#include <math.h>
+
+int bin2dec(char str[])
+{
+    int v = 0;
+    int l = 0;
+    while(str[l]) l++; 
+    for (int i = 0; str[i]; i++)
+    {
+        v += (str[i] - '0') << (l - i - 1);
+    }
+    return v;
+}
+
+int main()
+{
+    char str[] = "00001010";
+
+    std::cout << bin2dec(str);
+
+    return 0;
+}

BitsFunctions/main.cpp

@@ -0,0 +1,31 @@
+#include <iostream>
+
+int onBit(unsigned int num, unsigned int n)
+{
+    unsigned int m = 1 << n;
+    num = num | m;
+    return num;
+}
+
+int offBit(unsigned int num, unsigned int n)
+{
+    unsigned int m = 1 << n;
+    m = ~m;
+    return num & m;
+}
+
+int reverse(unsigned int num, unsigned int n)
+{
+    unsigned int m = 1 << n;
+    num = num ^ m;
+    return num;
+}
+
+int main()
+{
+    printf("%d\n", onBit(10, 0));
+    printf("%d\n", offBit(10, 3));
+    printf("%d", reverse(9, 0));
+
+    return 0;
+}

Blur/main.cpp

@@ -0,0 +1,74 @@
+#include <iostream>
+#include <cstdlib>
+#include <ctime>
+
+void conv(double begin[][4], double end[][4], int row, int col)
+{
+    for (int x = 0; x < row; x++)
+    {
+        for (int y = 0; y < col; y++)
+        {
+            end[x][y] = begin[x][y];
+            if (x - 1 >= 0)
+            {
+                end[x][y] += begin[x - 1][y];
+            }
+            if (x + 1 < row)
+            {
+                end[x][y] += begin[x + 1][y];
+            }
+            if (y - 1 >= 0)
+            {
+                end[x][y] += begin[x][y - 1];
+            }
+            if (y + 1 < col)
+            {
+                end[x][y] += begin[x][y + 1];
+            }
+            end[x][y] /= 5;
+        }
+    }
+}
+
+int main()
+{
+    srand(time(NULL));
+
+    const int row = 4;
+    const int col = 4;
+
+    double begin[row][col];
+    double end[row][col] = {0};
+
+    for (int x = 0; x < row; x++)
+    {
+        for (int y = 0; y < col; y++)
+        {
+            begin[x][y] = rand() % 255;
+        }
+    }
+
+    for (int x = 0; x < row; x++)
+    {
+        for (int y = 0; y < col; y++)
+        {
+            printf("%.3f ", begin[x][y]);
+        }
+        printf("\n");
+    }
+
+    printf("\n");
+
+    conv(begin, end, row, col);
+
+    for (int x = 0; x < row; x++)
+    {
+        for (int y = 0; y < col; y++)
+        {
+            printf("%.3f ", end[x][y]);
+        }
+        printf("\n");
+    }
+
+    return 0;
+}

ConsoleApp/main.cpp

@@ -0,0 +1,10 @@
+#include <iostream>
+#include <cstdlib>
+#include <ctime>
+
+int main()
+{
+    std::cout << "Hello world";
+    
+    return 0;
+}

CountWordsInString/main.cpp

@@ -0,0 +1,37 @@
+#include <iostream>
+
+int fun(const char[]);
+
+int main()
+{
+	char str[] = "h   ell  oworld";
+
+	printf("words num = %d", fun(str));
+
+	return 0;
+}
+
+int fun(const char str[])
+{
+	int count = 0;
+	for (int i = 0; str[i]; i++)
+	{
+		if (str[i] != ' ')
+		{
+			for (i;; i++)
+			{
+				if (str[i] == ' ')
+				{
+					break;
+				}
+				else if (str[i] == '\0')
+				{
+					i--;
+					break;
+				}
+			}
+			count++;
+		}
+	}
+	return count;
+}

DoubleTroubles/main.cpp

@@ -0,0 +1,21 @@
+#include <iostream>
+#include <ctime>
+
+double randomDouble(double, double);
+
+int main()
+{
+    srand(time(NULL));
+
+    for (int i = 0; i < 100; i++)
+    {
+        printf("%f\n", randomDouble(-5.0, 3.0));
+    }
+
+    return 0;
+}
+
+double randomDouble(double min, double max)
+{
+    return min + ((double)rand() / RAND_MAX) * (max - min);
+}

Fib/main.cpp

@@ -0,0 +1,43 @@
+#include <iostream>
+
+int fibIt(int);
+int fibRek(int);
+
+int main()
+{
+    unsigned int index;
+    std::cin >> index;
+
+    printf("%d\n", fibIt(index));
+    printf("%d", fibRek(index));
+    return 0;
+}
+
+int fibRek(int idx)
+{
+    if (idx == 0)
+    {
+        return 0;
+    }
+    if (idx < 3)
+    {
+        return 1;
+    }
+    return fibRek(idx - 1) + fibRek(idx - 2);
+}
+
+int fibIt(int idx)
+{
+    int n1 = 0;
+    int n2 = 1;
+    int n3;
+    if (idx == 1)
+        return n1;
+    for (int i = 1; i < idx - 1; i++)
+    {
+        n3 = n1 + n2;
+        n1 = n2;
+        n2 = n3;
+    }
+    return n3;
+}