7-1 考试周 (5point(s))

Submission

#include<iostream>
#include<iomanip>

using namespace std;
int main()
{
    int a, b; cin >> a >> b;
    
    cout << a << "/";
    cout << std::setprecision(1) << fixed << double(a) / b;
    cout << "=" << b;
}

7-2 真的恭喜你 (10point(s))

Submission

#include <iostream>
using namespace std;

int main() {
    int mark; cin >> mark;
    if(mark >= 90) cout << "gong xi ni kao le " << mark << " fen!";
    else cout << "kao le " << mark << " fen bie xie qi!";
    return 0;
}

7-3 平均成绩 (10point(s))

Submission

#include <iostream>
#include <iomanip>

using namespace std;
int main() {
    int n; cin >> n;

    int boy = 0, girl = 0;
    int boy_count = 0, girl_count = 0;
    while(n--) {
        int sex, mark;
        cin >> sex >> mark;
        if(sex == 0) {
            girl_count++;
            girl += mark;
        } else {
            boy_count++;
            boy += mark;
        }
    }

    cout << setprecision(1) << fixed << (girl + boy) / double(girl_count + boy_count) << " ";

    if(boy_count) cout << setprecision(1) << fixed << boy / double(boy_count) << " ";
    else cout << "X ";

    if(girl_count) cout << setprecision(1) << fixed << girl / double(girl_count);
    else cout << "X";

    return 0;
}

7-4 古风A+B (15point(s))

Submission

#include <iostream>
#include <vector>
using namespace std;
int main() {
    int a, b; cin >> a >> b;
    int s = a + b;
    if(s == 0) {
        cout << 0;
        return 0;
    }
    if(s < 0) {
        cout << "-\n";
        s = -s;
    }
    vector<int> res;
    for(; s > 0; s /= 10) {
        res.push_back(s % 10);
    }

    for(int i = res.size() - 1; i >= 0; --i) {
        cout << res[i] << endl;
    }

    return 0;
}

7-5 猜近似数字 (15point(s))

Submission

#include <iostream>
using namespace std;
bool solve(string& target, string& guess)
{
    bool onetime = false;
    if(target.size() != guess.size()) return false;
    for(int i = 0; i < target.size(); ++i) {
        if(guess[i] != target[i]) {
            if(guess[i] == target[i] - 1 || guess[i] == target[i] + 1) {
                if(onetime) return false;
                onetime = true;
            } else {
                return false;
            }
        }
    }
    return true;
}
int main() {

    string t; cin >> t;
    string g;
    while(cin >> g) {
        if(g == "-1") break;

        solve(t, g) ? cout << "Yes" : cout << "No";
        cout << endl;
    }
    return 0;
}

7-6 随机输一次 (20point(s))

Submission

#include <iostream>
#include <vector>
using namespace std;

const string chuizi = "ChuiZi";
const string jiandao = "JianDao";
const string bu = "Bu";

string lose(string in)
{
    if(in == chuizi) return jiandao;
    if(in == jiandao) return bu;
    if(in == bu) return chuizi;
}

string win(string in)
{
    if(in == chuizi) return bu;
    if(in == bu) return jiandao;
    if(in == jiandao) return chuizi;
}
int main() {
    int t; cin >> t;
    vector<int> r(t);
    for(int i = 0; i < t; ++i) {
        cin >> r[i];
    }
    string in;
    int pointer = 0;
    int count = 0;
    while(cin >> in) {
        if(in == "End") break;

        count++;
        if(count > r[pointer]) {
            cout << lose(in);
            count = 0;
            pointer = (pointer + 1) % t;
        } else cout << win(in);

        cout << endl;
    }
    return 0;
}

7-7 阶乘的非零尾数 (20point(s))

Submission

#include <iostream>
#include <cmath>
#include <iomanip>
using namespace std;

int cnt = 0;

void eliminate(long& n, int nMask)
{
    while(n % 10 == 0) {
        cnt++;
        n /= 10;
    }
    long mask = floor(pow(10, nMask) + 0.5);
    n %= mask;
}
int main() {
    int N, K; cin >> N >> K;

    long res = 1;
    for(int i = 1; i <= N; ++i) {
        res *= i;
        eliminate(res, K);
    }
    cout << setw(K) << setfill('0') << res;
    cout << " " << cnt;
    return 0;
}

7-8 三足鼎立 (25point(s))

Submission

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    int n; cin >> n;
    int P; cin >> P;

    vector<int> others(n);
    for(int i = 0; i < n;++i) {
        cin >> others[i];
    }

    sort(others.begin(), others.end());

    int count = 0;
    for(auto iter = others.begin(); iter != others.end(); advance(iter, 1)) {
        auto ub = upper_bound(next(iter), others.end(), P + *iter);
        auto lb = lower_bound(next(iter), others.end(), abs(P - *iter));
        count += (ub - lb);
    }
    cout << count;
    return 0;
}