add problem set answer 1

ps1a.py

@@ -0,0 +1,19 @@
+#!/usr/bin/env python
+#-*- coding:utf-8 -*-
+"""
+module: ps1a
+"""
+def main():
+    primes = [2, 3]
+    i = 3
+    while len(primes) < 1000:
+        i += 2
+        for j in primes:
+            if i % j == 0:
+                break
+        else:
+            primes.append(i)
+    print primes[1000-1]
+
+if __name__=="__main__":
+    main()

ps1a_2.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python
+#-*- coding:utf-8 -*-
+"""
+module: ps1a_2
+"""
+count = 2
+v = 3
+
+while count < 1000:
+    for i in range(2, v):
+        if v % i == 0:
+            break
+    else:
+        count += 1
+    v += 2
+print v

ps1b.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python
+#-*- coding:utf-8 -*-
+"""
+module: ps1b
+"""
+from math import *
+
+def process(n):
+    count = 2
+    v = 3
+    result = log(2) + log(3)
+
+    while count < n:
+        for i in range(2, v):
+            if v % i == 0:
+                break
+        else:
+            count += 1
+            result += log(v)
+        v += 1
+
+    print n, ": ", result
+    return n
+
+x = range(11, 200)
+y = [process(i)
+     for i in range(11, 200)]
+
+import numpy as np
+import matplotlib.pyplot as plt
+
+plt.plot(x, y)