[BZOJ4731][UOJ267]魔法小程序

先把代码读懂，可以理解成为c是b的高维前缀和
a[i] 是第 i 维的长度
显然长度大于1的维数不会超过 log2(m)
暴力还原回b就行了

#include 
#define INF 2147483647
#define N 1000050
using namespace std;
typedef long long LL;
LL a[10050],c[N],sum[N];
int n,m;
inline LL rd() {
    LL x=0,f=1;char ch=getchar();
    while (ch<'0'||ch>'9') {if(ch=='-')f=-1;ch=getchar();}
    while (ch>='0'&&ch<='9') {x=x*10+ch-'0';ch=getchar();}
    return x*f;
}
int main() {
    n = rd(); printf("%d\n",n);
    for (int i=0;iprintf("%lld%c",v,i==n-1?'\n':' ');
        v==1 ? n--,i-- : a[i] = v;
    }
    m = rd(), a[n++] = INF;
    for (int i=0;i0] = 1;
    for (int i=1;i1LL * a[i-1] * sum[i-1];
        if (sum[i] > m) { n = i; break; }
    }

    for (int j=0;jint x = m % sum[j], y = m / sum[j] % a[j];
        for (int i=m-1;i>=0;i--) {
            if (x) --x; else {
                x = sum[j] - 1;
                if (y) --y; else y = a[j] - 1;
            }
            if (y) c[i] -= ( c[i-sum[j]] );
        }
    }

    printf("%d\n",m);
    for (int i=0;iprintf("%lld%c",c[i],i==m-1?'\n':' ');
    return 0;
}