SCU2016-01 K找规律

Analyse:
很明显这个题是固定的，所以需要预先打表。
Get:
找规律递推就可以了。

/**********************jibancanyang************************** *Author*        :jibancanyang *Created Time*  : 一  7/ 4 13:59:02 2016**Problem**:**Code**:***********************[e-mail]**********************/#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>#include <vector>#include <queue>#include <set>#include <map>#include <string>#include <cmath>#include <cstdlib>#include <ctime>#include <stack>using namespace std;typedef pair<int, int> pii;typedef long long ll;typedef unsigned long long ull;typedef vector<int> vi;#define pr(x) cout << #x << ": " << x << "  " #define pl(x) cout << #x << ": " << x << endl;#define pri(a) printf("%d\n",(a))#define xx first#define yy second#define sa(n) scanf("%d", &(n))#define sal(n) scanf("%lld", &(n))#define sai(n) scanf("%I64d", &(n))#define vep(c) for(decltype((c).begin() ) it = (c).begin(); it != (c).end(); it++) const int mod = int(1e9) + 7, INF = 0x3f3f3f3f;const int maxn = 1e5 + 13;ll dp[maxn * 10];int main(void){#ifdef LOCAL    freopen("in.txt", "r", stdin);    //freopen("out.txt", "w", stdout);#endif    int n;    dp[3] = 0;    for (int i = 4; i <= 1000000 ; i++) {        dp[i] = dp[i - 1];        ll k = i - 3;        ll t = (k + 1) / 2;        dp[i] += k * t + t - t * t;    }    while (sa(n), n > 2) {        printf("%lld\n", dp[n]);    }    return 0;}