Added a C++ equation grapher

1 files changed, 63 insertions, 0 deletions

diff --git a/C++/QuadraticEquationGrapher.cpp b/C++/QuadraticEquationGrapher.cpp
new file mode 100644
index 0000000..7dfbe64
--- /dev/null
+++ b/C++/QuadraticEquationGrapher.cpp
@@ -0,0 +1,63 @@
+#include <iostream>
+#include <math.h>
+
+using namespace std;
+
+/* Program that graphs a quadratic equation on the standard output */
+
+/* Equation precision - how precise the quadratic equation result should be
+ * - higher values are more precise, but they could not show up on the graph
+ * - needs to be balanced with step
+ * Step - size of each unit (character)
+ */
+const int eqPrec  = 1;
+const double step = 1;
+
+const char line    = '*';
+const char verLine = '|';
+const char horLine = '-';
+const char empty   = ' ';
+
+double quadr(double x, double a, double b, double c) {
+    return double( round( ( (a*pow(x, 2)) + (b*x) + c) * eqPrec ) / eqPrec);
+}
+
+void printQadr(int startx, int endx, int starty, int endy, double a, double b, double c) {
+    double currY, currX;
+    for (int y = max(starty, endy); y >= min(starty, endy); y--) {
+        for (int x = startx; x <= endx; x++) {
+            currY = y * step;
+            currX = x * step;
+
+            if (quadr(currX, a, b, c) == currY 
+                || ((quadr(currX, a, b, c) < currY 
+                    || (quadr(currX - step, a, b, c) == 0 || quadr(currX + step, a, b, c) == 0)) // Wide lines
+                   && (quadr(currX + step, a, b, c) > currY != quadr(currX - step, a, b, c) > currY)) // Long lines  
+            ) {
+                cout << line;
+            } else if (x == 0) {
+                cout << verLine;
+            } else if (y == 0) {
+                cout << horLine;
+            } else {
+                cout << empty;
+            }
+        }
+        cout << endl;
+    }
+}
+
+void printQadr(int start, int end, double a, double b, double c) {
+    printQadr(start, end, start, end, a, b, c);
+}
+
+int main()
+{
+   double a = 0.2;
+   double b =   2;
+   double c = -10;
+   
+   printQadr(-25, 15, 20, -15, a, b, c);
+
+   return 0;
+}