{"trustable":false,"sections":[{"title":"","value":{"format":"HTML","content":"\n \u003cdiv class\u003d\"ptx\" lang\u003d\"en-US\"\u003e\n 给你四个数列A,B,C,D。从每个数列中各取出一个数,使4个数的和为0.\u003cbr\u003e当一个数列中有多个相同的数字的时候,把它们当做不同的数对待\n \u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\n \u003cdiv class\u003d\"ptx\" lang\u003d\"en-US\"\u003e\n 第一行:n(代表数列中数字的个数) (1≤n≤4000) \u003cbr\u003e\n 第二行:依次输入A,B,C,D(输入一个A再输入一个B)\n \u003c/div\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\n \u003cdiv class\u003d\"ptx\" lang\u003d\"en-US\"\u003e\n 输出不同组合的个数。\n \u003c/div\u003e"}},{"title":"Sample Input","value":{"format":"HTML","content":"\u003cpre class\u003d\"sio\"\u003e6\n-45 22 42 -16\n-41 -27 56 30\n-36 53 -37 77\n-36 30 -75 -46\n26 -38 -10 62\n-32 -54 -6 45\n\u003c/pre\u003e"}},{"title":"Sample Output","value":{"format":"HTML","content":"\u003cpre class\u003d\"sio\"\u003e5\n\u003c/pre\u003e"}},{"title":"Hint","value":{"format":"HTML","content":"\n \u003cdiv class\u003d\"ptx\" lang\u003d\"en-US\"\u003e\n Sample Explanation: Indeed, the sum of the five following quadruplets is zero: (-45, -27, 42, 30), (26, 30, -10, -46), (-32, 22, 56, -46),(-32, 30, -75, 77), (-32, -54, 56, 30). \n \u003c/div\u003e"}}]}