数学期望

在某种情况下赢，必定会在另一种情况下输。

所以在某种情况下获胜的期望是+获胜的期望-失败的期望。

#include 
    
     #define INF 0x3f3f3f3f#define full(a, b) memset(a, b, sizeof a)#define FAST_IO ios::sync_with_stdio(false), cin.tie(0), cout.tie(0)using namespace std;typedef long long ll;inline int lowbit(int x){ return x & (-x); }inline ll read(){    int ret = 0, w = 0; char ch = 0;    while(!isdigit(ch)) { w |= ch == '-'; ch = getchar(); }    while(isdigit(ch)) ret = (ret << 3) + (ret << 1) + (ch ^ 48), ch = getchar();    return w ? -ret : ret;}inline ll gcd(ll a, ll b){ return b ? gcd(b, a % b) : a; }inline ll lcm(ll a, ll b){ return a / gcd(a, b) * b; }template 
     
      inline T max(T x, T y, T z){ return max(max(x, y), z); }template 
      
       inline T min(T x, T y, T z){ return min(min(x, y), z); }template 
       
        inline A fpow(A x, B p, C lyd){    A ans = 1;    for(; p; p >>= 1, x = 1LL * x * x % lyd)if(p & 1)ans = 1LL * x * ans % lyd;    return ans;}int main(){    int _;    for(_ = (int)read(); _; _ --){        ll a1 = read(), b1 = read(), c1 = read();        ll a2 = read(), b2 = read(), c2 = read();        ll t = a1 + b1 + c1;        ll p = b2 * (a1 - c1) + c2 * (b1 - a1) + a2 * (c1 - b1);        if(p % t){            ll f = gcd(p, t);            f = labs(f);            cout << p / f << "/" << t / f << endl;        }        else cout << p / t << endl;    }    return 0;}