51nod2000 四边形分割平面 规律题

观察样例，$ans(1) = 1, ans(2) = 10$，再手推一组，$ans(3) = 26$

可以发现规律$ans(n) = (2n - 1)^2 + 1$

如果还是没看出规律，那么打个程序去骗组数据

更明显了，是吧.....

证明很简单，懒得证了

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;

extern inline char gc() {
    static char RR[], *S = RR + , *T = RR + ;
    if(S == T) fread(RR, , , stdin), S = RR;
    return *S ++;
}
inline int read() {
    int p = , w = ; char c = gc();
    while(c > '' || c < '') { if(c == '-') w = -; c = gc(); }
    while(c >= '' && c <= '') p = p *  + c - '', c = gc();
    return p * w;
}

#define ll long long
#define ri register int

int main() {
    int Tt = read();
    for(ri i = ; i <= Tt; i ++) {
        int n =  * read() - ;
        printf("%lld\n", 1ll * n * n + );
    }
    return ;
}