update

figs/problem1.dot

@@ -0,0 +1,22 @@
+digraph pdf {
+    entry [label="enter f()",style=filled];
+	entry -> {while; D};
+	while [label="while (X)",style=filled];
+    C [style="bold,filled"]
+    "if (Y)" [style=filled]
+    "if (Z)" [style=filled]
+	while -> {"if (Y)" C};
+    break2 [style=filled]
+    break1 [style=filled]
+	"if (Y)" -> {"if (Z)"};
+	"if (Z)" -> {A break1};
+	break1 -> B;
+	break1 -> break2;
+	break2 -> {C while};
+	{rank=same; A break1 B break2}
+	{rank=same; "if (Z)" C}
+	{rank=same; while D}			
+	{edge [style=invis];
+		A -> break1 -> B -> break2;
+	}
+}

figs/problem2.dot

@@ -0,0 +1,29 @@
+digraph g {
+	"f()" [shape=box, rank=min, style = filled];
+		// Rank adjustment
+		{ node [style=filled]
+		{ rank = same; "int a = 1"; "while (a > 0)"; }
+		"if (a > 10)"; break;
+		}
+		{ rank = same; "print(a)"; "a++"; }
+		{ rank = max; "a++"; "print(a)"; }
+		"a++" [style="filled,bold"];
+		// Control flow
+		"f()" -> "while (a > 0)";
+		"f()" -> "int a = 1";
+		"while (a > 0)" -> "if (a > 10)";
+		"if (a > 10)" -> "break";
+		"break" -> "print(a)";
+		"break" -> "a++";
+		"break" -> "while (a > 0)";
+		// Data flow
+		{ edge [color = red];
+			"int a = 1" -> "while (a > 0)";
+			"int a = 1" -> "if (a > 10)";
+			"int a = 1" -> "print(a)";
+			"a++" -> "a++";
+			"a++" -> "while (a > 0)";
+			"a++" -> "if (a > 10)";
+			"a++" -> "print(a)" [constraint = true];
+		}
+	}

figs/problem3.dot

@@ -0,0 +1,40 @@
+digraph g {
+    enter [style = filled];
+    mxin [label = "x = x_in", style = filled];
+    try [style = filled];
+    x_in [label = "x_in = x", style = filled];
+    f [label = "f()", style = filled];
+    nr [label = "normal return"];
+    x_out_nr [label = "x = x_out"];
+    er [label = "error return"];
+    catch [label = "catch (Exception e)"];
+    x_out_catch [label = "x = x_out"];
+    log [label = "log(\"error\")"];
+    x_0 [label = "x = 0", style = filled];
+    x_in2 [label = "x_in = x", style = filled];
+    f2 [label = "f()", style = filled];
+    nr2 [label = "normal return"];
+    er2 [label = "error return"];
+    ee [label = "error exit"];
+    x_out_nr2 [label = "x = x_out"];
+    x_out_ee [label = "x = x_out"];
+
+    enter -> {mxin try};
+    try -> f -> {x_in nr er}
+    nr -> x_out_nr
+    er -> catch -> {x_out_catch log}
+    enter -> {x_0 f2}
+    f2 -> {x_in2 nr2 er2}
+    nr2 -> x_out_nr2
+    er2 -> ee -> x_out_ee; 
+
+    {edge [color = red, constraint = false];
+        mxin -> x_in;
+        x_0 -> x_in2;
+    }
+
+    {edge [color = blue, constraint = false];
+    x_in -> {x_out_nr x_out_catch}
+    x_in2 -> {x_out_nr2 x_out_ee}
+    }
+}