【CPE】一顆星選集(Part 2) | C++

The 3n + 1 problem

題目：https://onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=3&page=show_problem&problem=36#google_vignette

中文題目：https://zerojudge.tw/ShowProblem?problemid=c039

#include <iostream>
using namespace std;

int main() {
    int i, j;
    while (cin >> i >> j) {
        int mx = 0;
        for (int n=min(i, j); n<=max(i, j); n++) {
            int n1 = n, cnt = 1;
            while (n1 != 1) {
                if (n1 % 2) n1 = 3*n1 + 1;
                else n1 /= 2;
                cnt++;
            }
            mx = max(mx, cnt);
        }
        cout << i << " " << j << " " << mx << "\n";
    }
    return 0;
}​

You can say 11

中文題目：https://zerojudge.tw/ShowProblem?problemid=d235

#include <iostream>
using namespace std;

int main() {
    string s;
    while (cin >> s) {
        if (s == "0") break;
        int odd = 0, even = 0;
        for (int i=0; i<s.size(); i++) {
            if (i % 2) {
                odd += s[i] - '0';
            } else {
                even += s[i] - '0';
            }
        }
        if ((odd - even) % 11 == 0) {
            cout << s << " is a multiple of 11.\n";
        } else {
            cout << s << " is not a mutiple of 11.\n";
        }
    }
    return 0;
}

Bangla Numbers

題目：https://onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=13&page=show_problem&problem=1042

#include <iostream>
#include <algorithm>
using namespace std;
#define ll long long
int a[] = {10000000, 100000, 1000, 100};
string s[] = {"kuti", "lakh", "hajar", "shata"};
string ans;

string num2str(ll x) {
    string s = "";
    while (x) {
        s += '0' + (x % 10);
        x /= 10;
    }
    reverse(s.begin(), s.end());
    return s;
}

void solve(ll x) {
    if (x >= a[0]) {
        solve(x / a[0]);
        ans += " " + s[0];
        x %= (int) a[0];
    }
    for (int i=0; i<4; i++) {
        if (x / a[i] > 0) {
            ans += " " + num2str(x / a[i]) + " " + s[i];
            x %= a[i];
        }
    }
    if (x > 0) ans += " " + num2str(x);
}

int main() {
    ll N;
    int Case = 1;
    while (cin >> N) {
        cout << "   " << Case++ << ".";
        if (N == 0) cout << " 0\n";
        else {
            ans = "";
            solve(N);
            cout << ans << "\n";
        }
    }
    return 0;
}