T1 [HAOI2016]放棋子
https://daniu.luogu.org/problem/show?pid=3182
障碍交换行不影响
所以第i列有障碍的行换到第i行
然后错排公式
本校自测要写压位高精，不写了。。。
#include<cstdio> #include<cstring> #include<algorithm> using namespace std; struct node { int len; int num[401]; void clear() { len=0; memset(num,0,sizeof(num)); } void operator = (int a) { len=0; while(a) len++,num[len]=a%10,a/=10; } void operator = (node a) { len=a.len; for(int i=1;i<=len;i++) num[i]=a.num[i]; } node operator + (node a) { node c; c.clear(); memset(c.num,0,sizeof(c.num)); int L=max(a.len,len); c.len=L; for(int i=1;i<=L;i++) c.num[i]=num[i]+a.num[i]; for(int i=1;i<=L;i++) if(c.num[i]>9) c.num[i+1]+=c.num[i]/10,c.num[i]%=10; if(c.num[L+1]) c.len++; while(c.num[c.len]>9) c.num[c.len+1]=c.num[c.len]/10,c.num[c.len]%=10,len++; if(c.num[c.len+1]) c.len++; return c; } node operator * (int a) { node c; c.clear(); int L; c.len=L=len; for(int i=1;i<=L;i++) c.num[i]=num[i]*a; for(int i=1;i<=L;i++) if(c.num[i]>9) c.num[i+1]+=c.num[i]/10,c.num[i]%=10; if(c.num[L+1]) c.len++; while(c.num[c.len]>9) c.num[c.len+1]=c.num[c.len]/10,c.num[c.len]%=10,len++; if(c.num[c.len+1]) c.len++; return c; } void print() { for(int i=len;i;i--) printf("%d",num[i]); } }; node f[201]; int main() { // freopen("firstmeet.in","r",stdin); // freopen("firstmeet.out","w",stdout); int n; scanf("%d",&n); f[1]=0,f[2]=1,f[3]=2; for(int i=4;i<=n;i++) { f[i].clear(); f[i]=(f[i-1]+f[i-2])*(i-1); } f[n].print(); }
T2 [Usaco2010 Dec]Exercise 奶牛健美操
http://www.lydsy.com/JudgeOnline/problem.php?id=2097
树形DP
#include<cstdio> #include<cstring> #include<iostream> #include<algorithm> #define N 100001 using namespace std; int front[N],to[N<<1],nxt[N<<1],tot; int dp[N],tmp[N]; int cnt,p; void read(int &x) { x=0; char c=getchar(); while(!isdigit(c)) c=getchar(); while(isdigit(c)) { x=x*10+c-'0'; c=getchar(); } } void add(int u,int v) { to[++tot]=v; nxt[tot]=front[u]; front[u]=tot; to[++tot]=u; nxt[tot]=front[v]; front[v]=tot; } bool dfs(int x,int y,int z) { int sum=0; for(int i=front[x];i;i=nxt[i]) if(to[i]!=y) { if(!dfs(to[i],x,z)) return false; } for(int i=front[x];i;i=nxt[i]) if(to[i]!=y) tmp[++sum]=dp[to[i]]+1; sort(tmp+1,tmp+sum+1); for(sum;tmp[sum]+tmp[sum-1]>z;sum--,cnt++); dp[x]=tmp[sum]; if(cnt>p) return false; return true; } bool check(int mid) { memset(dp,0,sizeof(dp)); cnt=0; return dfs(1,0,mid); } int main() { /* int size = 256 << 15; char *pp = (char*) malloc(size) + size; __asm__ ("movl %0, %%esp " :: "r"(pp)); freopen("longnosee.in","r",stdin); freopen("longnosee.out","w",stdout); */ int n; read(n), read(p); int u,v; for(int i=1;i<n;i++) { read(u),read(v); add(u,v); } int l=1,r=n,mid,ans; while(l<=r) { mid=l+r>>1; if(check(mid)) ans=mid,r=mid-1; else l=mid+1; } printf("%d",ans); }
T3
大爆搜，粘std啦
#include <cstdio> #include <iostream> #define rg register #define Max 22 inline void read (int &now) { rg char c = getchar (); for (now = 0; !isdigit (c); c = getchar ()); for (; isdigit (c); now = now * 10 + c - '0', c = getchar ()); } int _x[] = { 1, -1, 0, 0, 0, 0 }, _y[] = { 0, 0, 1, -1, 0, 0 }, _z[] = { 0, 0, 0, 0, 1, -1 }; int N, M, Z, P, Sx, Sy, Sz, St, Tt,Tx, Ty, Tz, Answer; bool is[Max][Max][Max], dot[Max][Max][Max]; inline bool Can (int x, int y, int z) { return x > 0 && x <= N && y > 0 && y <= M && z > 0 && z <= Z && !is[x][y][z] && !dot[x][y][z]; } inline int abs (int a) { return a < 0 ? -a : a; } void Dfs (int x, int y, int z, int t, int s) { int r = abs (x - Tx) + abs (y - Ty) + abs (z - Tz); if (s + (r >> 2) >= Answer) return ; if (x == Tx && y == Ty && z == Tz) { if (t == Tt) Answer = s; return ; } rg int i, a, b, c; if (Can (x + _x[t], y + _y[t], z + _z[t]) && Can (x + _x[t] * 2, y + _y[t] * 2, z + _z[t] * 2)) { is[x + _x[t]][y + _y[t]][z + _z[t]] = true; is[a = (x + _x[t] * 2)][b = (y + _y[t] * 2)][c = (z + _z[t] * 2)] = true; for (i = 0; i < 6; ++ i) if ((i >> 1) != (t >> 1) && Can (a + _x[i], b + _y[i], c + _z[i]) && Can (a + _x[i] * 2, b + _y[i] * 2, c + _z[i] * 2)) { is[a + _x[i]][b + _y[i]][c + _z[i]] = true; is[a + _x[i] * 2][b + _y[i] * 2][c + _z[i] * 2] = true; Dfs (a + _x[i] * 2, b + _y[i] * 2, c + _z[i] * 2, i, s + 1); is[a + _x[i]][b + _y[i]][c + _z[i]] = false; is[a + _x[i] * 2][b + _y[i] * 2][c + _z[i] * 2] = false; } if (Can (x + _x[t] * 3, y + _y[t] * 3, z + _z[t] * 3)) { is[a = (x + _x[t] * 3)][b = (y + _y[t] * 3)][c = (z + _z[t] * 3)] = true; for (i = 0; i < 6; ++ i) if ((i >> 1) != (t >> 1) && Can (a + _x[i], b + _y[i], c + _z[i])) { is[a + _x[i]][b + _y[i]][c + _z[i]] = true; Dfs (a + _x[i], b + _y[i], c + _z[i], i, s + 1); is[a + _x[i]][b + _y[i]][c + _z[i]] = false; } is[a = (x + _x[t] * 3)][b = (y + _y[t] * 3)][c = (z + _z[t] * 3)] = false; } is[x + _x[t]][y + _y[t]][z + _z[t]] = false; is[x + _x[t] * 2][y + _y[t] * 2][z + _z[t] * 2] = false; } } int Main () { freopen ("blessyou.in", "r", stdin); freopen ("blessyou.out", "w", stdout); read (N), read (M), read (Z), read (P); rg int i, j; int x, y, z; rg char c; if (N <= 2 && M <= 2 && Z <= 2) return printf ("Dream Battle"), 0; read (Sx), read (Sy), read (Sz); for (c = getchar (); c != 'x' && c != 'y' && c != 'z'; c = getchar ()); St = (c - 'x') << 1; if (c == 'x') St += (Sx == N); else if (c == 'y') St += (Sy == M); else if (c == 'z') St += (Sz == Z); Sx -= _x[St], Sy -= _y[St], Sz -= _z[St]; read (Tx), read (Ty), read (Tz); for (c = getchar (); c != 'x' && c != 'y' && c != 'z'; c = getchar ()); Tt = (c - 'x') << 1; if (c == 'x') Tt += (Tx == 1); else if (c == 'y') Tt += (Ty == 1); else if (c == 'z') Tt += (Tz == 1); for (i = 1; i <= P; ++ i) read (x), read (y), read (z), dot[x][y][z] = true; Answer = 13; Dfs (Sx, Sy, Sz, St, 0); if (Answer == 13) printf ("Dream Battle"); else printf ("%d", Answer); return 0; } int ZlycerQan = Main (); int main (int argc, char *argv[]) { return 0; }