本场题目不难，暴力模拟大法好。A~E：模拟+暴力（有些是贪心）；F：留坑待填；G：埃氏筛+贪心。
A、Restoring Three Numbers
思路：简单数学。
AC代码：
1 #include <cstdio> 2 #include <cstring> 3 #include <cstdlib> 4 #include <cmath> 5 #include <iostream> 6 #include <algorithm> 7 #include <iomanip> 8 #include <complex> 9 #include <string> 10 #include <vector> 11 #include <set> 12 #include <map> 13 #include <list> 14 #include <deque> 15 #include <queue> 16 #include <stack> 17 #include <bitset> 18 using namespace std; 19 typedef long long LL; 20 typedef unsigned long long ULL; 21 const int dir[4][2] = {{-1, 0}, {0, 1}, {1, 0}, {0, -1}}; // 上右下左 22 const int mx[8] = {-1, -2, -2, -1, 1, 2, 2, 1}; // 马可走的八个方向 23 const int my[8] = {-2, -1, 1, 2, 2, 1, -1, -2}; 24 const double eps = 1e-6; 25 const double PI = acos(-1.0); 26 const int maxn = 1e5+5; 27 const int inf = 0x3f3f3f3f; 28 29 30 LL x[5], a, b, c; 31 32 int main() { 33 while(cin >> x[1] >> x[2] >> x[3] >> x[4]) { 34 sort(x + 1, x + 5); 35 b = (x[1] - x[2] + x[3]) / 2; 36 c = x[3] - b; 37 a = x[4] - b - c; 38 cout << a << ' ' << b << ' ' << c << endl; 39 } 40 return 0; 41 }