算法入门-构造算法

BGN72 茉茉的密码

//茉茉的密码
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int INF = 0x3f3f3f3f;
#define sz size()
int main () {
    ios_base::sync_with_stdio (false);
    cin.tie (0);
    map<char,ll> m;

    int n;
    cin >> n;
    vector<string> v(n);
    for (int i=0;i<n;i++) cin >> v[i];
    for (int i=0;i<n;i++) {
        map<char,ll> mo;
        for (int j=0;j<v[i].sz;j++) {
            if(!mo[v[i][j]]){
                mo[v[i][j]]++;
                m[v[i][j]]++;
            }
        }
    }
    for (const auto s: m) {
        if (s.second ==n) {
            cout << s.first;
            return 0;
        }
    }
}

BGN73

#include <iostream>
using namespace std;

int main() {
    int x;
    cin>>x;
    if(x==1){
        cout<<-1;
        return 0;
    }
    cout<<x<<' '<<x;
}

BGN74

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define sz size()
#define vll vector<long long>
using ll=long long;
using ull = unsigned long long;
const int MOD1=1e9+7;
const int MOD2=998244353;
void solve() {
    ll n,k;
    cin>>n>>k;
    vector<vector<int>> v(n,vector<int>(n,0));
    for (int i=0;i<n;i++) {
        v[i][i]=k;
    }
    for (int i=0;i<n;i++) {
        for (int j=0;j<n;j++) {
            cout<<v[i][j]<<" ";
        }
        cout<<'\n';
    }
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(nullptr);
    int t=1;
    //cin>>t;
    while (t--) {
        solve();
    }
}

BGN76

//
// Created by XIAOBAI on 2026/6/2.
//
#include <bits/stdc++.h>
using namespace std;
const int MOD1 = 1e9 + 7;
const int MOD2 = 998244353;
using ll = long long;
using ull = unsigned long long;
bool cmp(int a,int b) {
    return a>b;
}

ll get(ll x) {
    if (x==0) return 0;
    if (x==1) return 1;
    return get(x/2)+get(x%2);
}
void solve() {
    ll n;
    cin>>n;
    cout<<get(n);

}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int T=1;
    cin>>T;
    while(T--) {
        solve();
    }

}