Week 4, Class 2.ipynb

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   "source": [
    "# Week 4, Class 2\n",
    "## Recursive functions\n"
   ]
  },
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   "execution_count": 6,
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     "text": [
      "100\n"
     ]
    }
   ],
   "source": [
    "# Starting point?\n",
    "# ending point?\n",
    "# increment/decrement?\n",
    "\n",
    "def countdown(n):\n",
    "    if n>=10:     #base condition\n",
    "        print(n)\n",
    "    else:\n",
    "        print(n)\n",
    "        n=n+1\n",
    "        countdown(n)\n",
    "\n",
    "countdown(100)"
   ]
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     "text": [
      "3628800\n"
     ]
    }
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   "source": [
    "def fact(n):\n",
    "    if n==0:\n",
    "        return 1\n",
    "    else:\n",
    "        return n*fact(n-1)\n",
    "    \n",
    "print(fact(10)) "
   ]
  },
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   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
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     "text": [
      "120\n"
     ]
    }
   ],
   "source": [
    "def factorial(n):\n",
    "    f=1\n",
    "    for x in range(n, 0, -1):\n",
    "        f=f*x     \n",
    "    return f\n",
    "  \n",
    "print(factorial(5))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Hello\n",
      "Hello\n",
      "Hello\n",
      "Hello\n"
     ]
    }
   ],
   "source": [
    "def print_s(s, n):\n",
    "    if n<=0:                #Base case \n",
    "        return\n",
    "    print(s)\n",
    "    print_s(s, n-1)\n",
    "    \n",
    "print_s(\"Hello\", 4)\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 25,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
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     "text": [
      "8\n",
      "13\n"
     ]
    }
   ],
   "source": [
    "def fib(n):\n",
    "    if n==0:\n",
    "        return 0\n",
    "    if n==1:\n",
    "        return 1\n",
    "    return fib(n-1)+fib(n-2)\n",
    "\n",
    "print(fib(6))\n",
    "print(fib(7))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 26,
   "metadata": {},
   "outputs": [
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     "text": [
      "15\n"
     ]
    }
   ],
   "source": [
    "def f(a):\n",
    "    return a+10\n",
    "\n",
    "print(f(5))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 27,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "25\n"
     ]
    }
   ],
   "source": [
    "f = lambda a: a+10\n",
    "print(f(15))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 32,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "5\n"
     ]
    }
   ],
   "source": [
    "def add(a,b):\n",
    "    return a+b\n",
    "\n",
    "s = lambda a, b : a+b\n",
    "print(s(2,3))"
   ]
  },
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   "execution_count": 34,
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     "text": [
      "0\n",
      "1\n",
      "2\n"
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    }
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   "source": [
    "def infinite_sequence():\n",
    "    num =0\n",
    "    while True:\n",
    "        yield num\n",
    "        num += 1\n",
    "\n",
    "gen = infinite_sequence()\n",
    "print( next(gen) )\n",
    "print( next(gen) )\n",
    "print( next(gen) )\n"
   ]
  }
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