5. Вывод гистограммы как изображения в формате SVG

main.cpp

@@ -2,6 +2,7 @@
 #include <vector>
 #include "histogram.h"
 #include "text.h"
+#include "svg.h"
 using namespace std;
 
 struct Input {
@@ -33,10 +34,37 @@ Input input_data() {
     return in;
 }
 
+void show_histogram_svg(const vector<size_t>& bins) {
+    const auto IMAGE_WIDTH = 400;
+    const auto IMAGE_HEIGHT = 300;
+    const auto TEXT_LEFT = 20;
+    const auto TEXT_BASELINE = 20;
+    const auto TEXT_WIDTH = 50;
+    const auto BIN_HEIGHT = 30;
+    const auto BLOCK_WIDTH = 10;
+
+    svg_begin(IMAGE_WIDTH, IMAGE_HEIGHT);
+
+    size_t max_count = 0;
+    for (size_t count : bins) {
+        if (count > max_count) max_count = count;
+    }
+
+    double top = 0;
+    for (size_t bin : bins) {
+        const double bin_width = (max_count > 0) ?
+            (static_cast<double>(bin) / max_count * (IMAGE_WIDTH - TEXT_WIDTH)) : 0;
+        svg_text(TEXT_LEFT, top + TEXT_BASELINE, to_string(bin));
+        svg_rect(TEXT_WIDTH, top, bin_width, BIN_HEIGHT, "black", "#aaffaa");
+        top += BIN_HEIGHT;
+    }
+
+    svg_end();
+}
+
 int main() {
     auto input = input_data();
     auto bins = make_histogram(input.numbers, input.bin_count);
-    show_histogram_text(bins);
+    show_histogram_svg(bins);
-
     return 0;
 }

svg.cpp

@@ -0,0 +1,26 @@
+#include "svg.h"
+#include <iostream>
+
+using namespace std;
+
+void svg_begin(double width, double height) {
+    cout << "<?xml version='1.0' encoding='UTF-8' ?>\n";
+    cout << "<svg width='" << width << "' height='" << height << "' "
+         << "viewBox='0 0 " << width << " " << height << "' "
+         << "xmlns='http://www.w3.org/2000/svg'>\n";
+}
+
+void svg_end() {
+    cout << "</svg>\n";
+}
+
+void svg_text(double left, double baseline, const std::string& text) {
+    cout << "<text x='" << left << "' y='" << baseline << "'>" << text << "</text>\n";
+}
+
+void svg_rect(double x, double y, double width, double height,
+              const std::string& stroke, const std::string& fill) {
+    cout << "<rect x='" << x << "' y='" << y << "' width='" << width
+         << "' height='" << height << "' stroke='" << stroke
+         << "' fill='" << fill << "' />\n";
+}

svg.h

@@ -0,0 +1,12 @@
+#ifndef SVG_H_INCLUDED
+#define SVG_H_INCLUDED
+
+#include <vector>
+#include <string>
+
+void svg_begin(double width, double height);
+void svg_end();
+void svg_text(double left, double baseline, const std::string& text);
+void svg_rect(double x, double y, double width, double height, const std::string& stroke = "black", const std::string& fill = "black");
+
+#endif // SVG_H_INCLUDED