Solve some problems.

python/e136.py

@@ -0,0 +1,37 @@
+def euler_136():
+    n = 10**8
+    threshold = 50*10**6
+    lookup = [0 for _ in range(0, threshold)]
+    firstpositivestart = 1
+    for x in range(1, n):
+        firstpositive = False
+        for dxy in range(firstpositivestart, x // 2 + 1):
+            z = x - 2 * dxy
+            if z <= 0:
+                break
+            y = x - dxy
+            xyz = x*x - y*y - z*z
+            if xyz <= 0:
+                continue
+
+            # Start when xyz is already greater than 0.
+            if not firstpositive:
+                firstpositivestart = dxy
+                firstpositive = True
+
+            # If xyz is greater than threshold there are no more solutions.
+            if xyz >= threshold:
+                break
+            lookup[xyz] += 1
+
+    r = 0
+    for v in lookup:
+        if v == 1:
+            r += 1
+    return r
+
+
+if __name__ == "__main__":
+    solution = euler_136()
+    print("e136.py: " + str(solution))
+    assert solution == 2544559