Solve some problems.

python/e135.py

@@ -0,0 +1,37 @@
+def euler_135():
+    n = 10**7
+    threshold = 10**6
+    lookup = {i: 0 for i in range(1, 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.items():
+        if v == 10:
+            r += 1
+    return r
+
+
+if __name__ == "__main__":
+    solution = euler_135()
+    print("e135.py: " + str(solution))
+    assert solution == 4989