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[23456], *S = RR + 23333, *T = RR + 23333; if(S == T) fread(RR, 1, 23333, stdin), S = RR; return *S ++; } inline int read() { int p = 0, w = 1; char c = gc(); while(c > '9' || c < '0') { if(c == '-') w = -1; c = gc(); } while(c >= '0' && c <= '9') p = p * 10 + c - '0', c = gc(); return p * w; } #define ll long long #define ri register int int main() { int Tt = read(); for(ri i = 1; i <= Tt; i ++) { int n = 2 * read() - 1; printf("%lld ", 1ll * n * n + 1); } return 0; }