uva10622 Perfect P-th Powers

留坑(p.343)

完全不知道哪里有问题qwq

从31向下开始枚举p，二分找存在性，或者数学函数什么的也兹辞啊

#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<iostream>

using namespace std;

void setIO(const string& s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}
template<typename Q> Q read(Q& x) {
    static char c, f;
    for(f = 0; c = getchar(), !isdigit(c); ) if(c == '-') f = 1;
    for(x = 0; isdigit(c); c = getchar()) x = x * 10 + c - '0';
    if(f) x = -x;
    return x;
}
template<typename Q> Q read() {
    static Q x; read(x); return x;
}

typedef long long LL;

LL qpow(LL a, LL b, LL Lim = ~0ull >> 1) {
    for(LL c = 1; ; a *= a) {
        if(b & 1) c *= a;
        if(!(b >>= 1)) return c;
        if(c > Lim || a > Lim) return -1;
    }
}

bool exist(LL x, LL p) {
    int l = 0, r = ~0u >> 1;
    while(l <= r) {
        int mid = l + (r - l) / 2;
        LL res = qpow(mid, p, x);
        if(res == x) return 1;
        else if(res == -1 || res > x) r = mid - 1;
        else l = mid + 1;
    }
    return 0;
}

int solve(LL n) {
    if(n == 1) return 1;
    int sign = 1;
    if(n < 0) sign = -1, n = -n;
    for(int p = 31; p >= 2; p -= (sign > 0 ? 1 : 2)) {
        if(exist(n, p)) return p;
    }
    return 1;
}

int main() {
#ifdef DEBUG
    freopen("in.txt", "r", stdin);
    freopen("out.txt", "w", stdout);
#endif
    int n;
    while(read(n)) {
        printf("%d
", solve(n));
    }
    
    return 0;
}