L2-029 特立独行的幸福

#include <bits/stdc++.h>

using namespace std;

bool isyifu[10010];
bool isunhappy[10010];
bool ishappy[10010];

int tran(int x) {
    int res = 0;
    while (x) {
        res = res + (x % 10) * (x % 10);
        x /= 10;
    }
    return res;
}

void check(int x, int l, int r) {
    set<int> S;
    S.insert(x);
    int m = tran(x);
    if (m == 1) {
        ishappy[x] = true;
        return;
    }
    isyifu[m] = true;
    bool ok = false;
    while (1) {
        m = tran(m);
        if (m == 1) { //变成1那么就是幸福的
            ishappy[x] = true;
            return;
        }
        if (m >= l && m <= r) isyifu[m] = true;
        if (S.count(m)) {
            ok = true;
            break;
        }
        S.insert(m);
    }
    if (ok) isunhappy[x] = true; //如果

    return;
}

bool isprime(int x) {
    if (x == 0 || x == 1) return false;
    for (int i = 2; i <= x / i; i++) {
        if (x % i == 0) return false;
    }
    return true;
}

//1是一个幸福数字

int work(int x, int l, int r) {
    int res = 0, temp = x;
    while (1) {
        if (x == 1) break;
        res += 1;
        x = tran(x); 
    }
    return res * (isprime(temp) ? 2 : 1);
}

int main() {
    int l, r;
    cin >> l >> r;
    for (int x = l; x <= r; x++) {
        check(x, l, r);
    }
    bool isSad = true;
    for (int x = l; x <= r; x++) {
        if (ishappy[x] && !isyifu[x]) {
            isSad = false;
            cout << x << " " << work(x, l, r) << "\n";
        }
    }
    if (isSad) cout << "SAD" << "\n";

    return 0;
}