【开源社区openEuler实践】 D. ConstructOR

题目

思路：

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pb push_back
#define fi first
#define se second
#define lson p << 1
#define rson p << 1 | 1
const int maxn = 1e6 + 5, inf = 1e18, maxm = 4e4 + 5;
const int N = sqrt(1e9) + 1;
 const int mod = 1e9 + 7;
// const int mod = 998244353;
//const __int128 mod = 212370440130137957LL;
// int a[505][5005];
// bool vis[505][505];

int a[maxn], b[maxn];
bool vis[maxn];
string s[maxn];
int n, m;

struct Node{
    int val, id;
    bool operator<(const Node &u)const{
        return val < u.val;
    }
};
// Node c[maxn];
int ans[maxn];

//long long ? maxn ? n? m?


void solve(){
    int res = 0;
    // int q, k;
    int x;
    int a, b, d;
    cin >> a >> b >> d;
    if(d % 2 == 0 && (a % 2 == 1 || b % 2 == 1)){
        cout << -1 << '\n';
        return;
    }
    a |= b;
    int k = 0;
    while((~a & 1) && (~d & 1)){
        a /= 2;
        d /= 2;
        k++;
    }
    if((a & 1) && (~d & 1)){
        cout << -1 << '\n';
        return;
    }
    int inv = (d + 1) / 2;
    int pw = 1;
    for(int i = 1; i <= 30 - k; i++){
        pw = pw * inv % d;
    }
    int p = (pw + d - 1) % d;
    x = (1LL << k) * (p * (1LL << (30 - k)) + (1LL << (30 - k)) - 1);
    cout << x << '\n';
}   
    
signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);

    int T = 1;
    cin >> T;
    while (T--)
    {
        solve();
    }
    return 0;
}