|BZOJ 1655|无限背包|高精度|[Usaco2006 Jan] Dollar Dayz 奶牛商店

BZOJ 1655
poj 3181
from: USACO 2006 Jan Sliver(USACO刷题第3题)

很容易看出本题是个无限背包方案数的dp，但是本题数据大会爆long long，那就可以把dp数组拆分为两个数组，类似于高精度压位地做

#include<cstdio>#include<cstring>#include<algorithm>#include<stack>#include<vector>#define ms(i, j) memset(i, j, sizeof i)#define LL long longusing namespace std;const int MAXN = 1000 + 5;const LL MOD = 1000000000000000000;int k, n;LL a[MAXN], b[MAXN];void clear() {    ms(a, 0), ms(b, 0);}void init() {    clear();    b[0] = 1;}void solve() {    for (int i=1;i<=k;i++) {        for (int j=i;j<=n;j++) {            a[j] = a[j] + a[j-i] + (b[j] + b[j-i]) / MOD;            b[j] = (b[j] + b[j-i]) % MOD;        }    }    if (a[n]==0) printf("%lld\n", b[n]); else    printf("%lld%018lld\n", a[n], b[n]);}int main() {    #ifndef ONLINE_JUDGE    freopen("1.in", "r", stdin);freopen("1.out", "w", stdout);    #endif    while (scanf("%d%d", &n, &k)==2&&n&&k) init(), solve();    return 0;}