Codeforces Round #763 (Div. 2) D.Robot Cleaner Revisit 期望/思维

|——>传送门>= 1, (x *= x) %= mod) if (y & 1) (res *= x) %= mod; return res; } inline int inv(int x){ return binpow(x, MOD - 2, MOD); } inline void solve(){ int n, m, rb, cb, rd, cd, p; cin >> n >> m >> rb >> cb >> rd >> cd >> p; p = p * inv(100) % MOD; int pre = 1, idx = 0, ans = 0, dr = 1, dc = 1; map mp; while(true){ if (rb + dr n) dr *= -1; if (cb + dc m) dc *= -1; if (mp[{rb, cb, dr, dc}]) break; else mp[{rb, cb, dr, dc}] = true; if (rb == rd || cb == cd) { ans = (ans + idx * pre % MOD * p % MOD) % MOD; pre = pre * (1 - p + MOD) % MOD; } rb += dr, cb += dc, idx++; } ans = ((ans + idx * pre % MOD) % MOD) * inv((1 - pre + MOD) % MOD) % MOD; cout