从后往前递推便可node
#include <bits/stdc++.h> #define fi first #define se second #define pii pair<int,int> #define mp make_pair #define pb push_back #define space putchar(' ') #define enter putchar('\n') #define eps 1e-10 #define MAXN 100005 //#define ivorysi using namespace std; typedef long long int64; typedef unsigned int u32; typedef double db; template<class T> void read(T &res) { res = 0;T f = 1;char c = getchar(); while(c < '0' || c > '9') { if(c == '-') f = -1; c = getchar(); } while(c >= '0' && c <= '9') { res = res * 10 +c - '0'; c = getchar(); } res *= f; } template<class T> void out(T x) { if(x < 0) {x = -x;putchar('-');} if(x >= 10) { out(x / 10); } putchar('0' + x % 10); } int N; int64 A[MAXN],B[MAXN]; void Solve() { read(N); for(int i = 1 ; i <= N ; ++i) {read(A[i]);read(B[i]);} int64 ans = 0,pre = 0; for(int i = N ; i >= 1 ; --i) { A[i] += pre; int64 tmp = (B[i] - A[i] % B[i]) % B[i]; pre += tmp; ans += tmp; } out(ans);enter; } int main() { #ifdef ivorysi freopen("f1.in","r",stdin); #endif Solve(); return 0; }
从叶子往根递推,在一个节点合并的时候从小到大合并,每次是当前值和合并的值最大值+1c++
#include <bits/stdc++.h> #define fi first #define se second #define pii pair<int,int> #define mp make_pair #define pb push_back #define space putchar(' ') #define enter putchar('\n') #define eps 1e-10 #define MAXN 100005 //#define ivorysi using namespace std; typedef long long int64; typedef unsigned int u32; typedef double db; template<class T> void read(T &res) { res = 0;T f = 1;char c = getchar(); while(c < '0' || c > '9') { if(c == '-') f = -1; c = getchar(); } while(c >= '0' && c <= '9') { res = res * 10 +c - '0'; c = getchar(); } res *= f; } template<class T> void out(T x) { if(x < 0) {x = -x;putchar('-');} if(x >= 10) { out(x / 10); } putchar('0' + x % 10); } struct node { int to,next; }E[MAXN * 2]; int N,sumE,head[MAXN],dep[MAXN]; void add(int u,int v) { E[++sumE].to = v; E[sumE].next = head[u]; head[u] = sumE; } void dfs(int u) { for(int i = head[u] ; i ; i = E[i].next) { int v = E[i].to; dfs(v); } vector<int> sec; for(int i = head[u] ; i ; i = E[i].next) { int v = E[i].to; sec.pb(dep[v]); } sort(sec.begin(),sec.end()); for(auto t : sec) { dep[u] = max(dep[u],t) + 1; } } void Solve() { read(N); int f; for(int i = 2 ; i <= N ; ++i) { read(f); add(f,i); } dfs(1); out(dep[1]);enter; } int main() { #ifdef ivorysi freopen("f1.in","r",stdin); #endif Solve(); return 0; }
\(dp[i][j]\)表示第一个集合最后一个是\(A[i]\),第二个集合最后一个是\(A[j]\),假如dp到第k个数,这二维必然有一个是k - 1,线段树优化转移便可优化
#include <bits/stdc++.h> #define fi first #define se second #define pii pair<int,int> #define mp make_pair #define pb push_back #define space putchar(' ') #define enter putchar('\n') #define eps 1e-10 #define MAXN 100005 //#define ivorysi using namespace std; typedef long long int64; typedef unsigned int u32; typedef double db; template<class T> void read(T &res) { res = 0;T f = 1;char c = getchar(); while(c < '0' || c > '9') { if(c == '-') f = -1; c = getchar(); } while(c >= '0' && c <= '9') { res = res * 10 +c - '0'; c = getchar(); } res *= f; } template<class T> void out(T x) { if(x < 0) {x = -x;putchar('-');} if(x >= 10) { out(x / 10); } putchar('0' + x % 10); } const int MOD = 1000000007; int N; int64 A,B,S[MAXN]; struct node { int sum[2],l,r,cov[2]; }tr[MAXN * 4]; int inc(int a,int b) { return a + b >= MOD ? a + b - MOD : a + b; } int mul(int a,int b) { return 1LL * a * b % MOD; } void update(int &x,int y) { x = inc(x,y); } void update(int u) { for(int i = 0 ; i < 2 ; ++i) tr[u].sum[i] = inc(tr[u << 1].sum[i],tr[u << 1 | 1].sum[i]); } void cover(int id,int u) { tr[u].cov[id] = 1; tr[u].sum[id] = 0; } void pushdown(int u) { for(int i = 0 ; i < 2 ; ++i) { if(tr[u].cov[i]) { cover(i,u << 1);cover(i,u << 1 | 1); tr[u].cov[i] = 0; } } } void build(int u,int l,int r) { tr[u].l = l;tr[u].r = r; if(l == r) return; int mid = (l + r) >> 1; build(u << 1,l,mid); build(u << 1 | 1,mid + 1,r); } void add(int id,int u,int x,int v) { if(tr[u].l == tr[u].r) { update(tr[u].sum[id],v);return; } pushdown(u); int mid = (tr[u].l + tr[u].r) >> 1; if(x <= mid) add(id,u << 1,x,v); else if(x > mid) add(id,u << 1 | 1,x,v); update(u); } void lid(int id,int u,int l,int r) { if(tr[u].l == l && tr[u].r == r) {cover(id,u);return;} pushdown(u); int mid = (tr[u].l + tr[u].r) >> 1; if(r <= mid) lid(id,u << 1,l,r); else if(l > mid) lid(id,u << 1 | 1,l,r); else {lid(id,u << 1,l,mid);lid(id,u << 1 | 1,mid + 1,r);} update(u); } int Query(int id,int u,int l,int r) { if(tr[u].l == l && tr[u].r == r) return tr[u].sum[id]; pushdown(u); int mid = (tr[u].l + tr[u].r) >> 1; if(r <= mid) return Query(id,u << 1,l,r); else if(l > mid) return Query(id,u << 1 | 1,l,r); else {return inc(Query(id,u << 1,l,mid),Query(id,u << 1 | 1,mid + 1,r));} } void Solve() { read(N);read(A);read(B); for(int i = 1 ; i <= N ; ++i) read(S[i]); build(1,0,N); add(0,1,0,1);add(1,1,0,1); for(int i = 2 ; i <= N ; ++i) { int t = upper_bound(S + 1,S + N + 1,S[i] - A) - S - 1; int va = Query(1,1,0,t); t = upper_bound(S + 1,S + N + 1,S[i] - B) - S - 1; int vb = Query(0,1,0,t); add(0,1,i - 1,va); add(1,1,i - 1,vb); if(S[i] - S[i - 1] < A) lid(0,1,0,i - 2); if(S[i] - S[i - 1] < B) lid(1,1,0,i - 2); } out(inc(tr[1].sum[0],tr[1].sum[1]));enter; } int main() { #ifdef ivorysi freopen("f1.in","r",stdin); #endif Solve(); return 0; }
大意:一个点的数值是1,每次能够选择一个中心点和周围最大价值为k的树合成一个k + 1的树,给定一棵树,问最小值是多少ui
其实就是转化成一个标号,若是这个点在k的树中做为中心点被选了,那么这个点标号为kspa
而后要求两个相同的数之间必须有一个比他们都大的数code
答案个数不超过log N,因此把每一个子树里不能选的数压成一个二进制数,父亲不能选的是全部子树不能选的并集,并且子树中如有两个数都不能选,则选择的数必须大于这个数ip
而后该点若选了t,比t小的值均可以标记为可选get
#include <bits/stdc++.h> #define fi first #define se second #define pii pair<int,int> #define mp make_pair #define pb push_back #define space putchar(' ') #define enter putchar('\n') #define eps 1e-10 #define MAXN 100005 //#define ivorysi using namespace std; typedef long long int64; typedef unsigned int u32; typedef double db; template<class T> void read(T &res) { res = 0;T f = 1;char c = getchar(); while(c < '0' || c > '9') { if(c == '-') f = -1; c = getchar(); } while(c >= '0' && c <= '9') { res = res * 10 +c - '0'; c = getchar(); } res *= f; } template<class T> void out(T x) { if(x < 0) {x = -x;putchar('-');} if(x >= 10) { out(x / 10); } putchar('0' + x % 10); } struct node { int to,next; }E[MAXN * 2]; int N,head[MAXN],sumE; int mask[MAXN],ans; void add(int u,int v) { E[++sumE].to = v; E[sumE].next = head[u]; head[u] = sumE; } void dfs(int u,int fa) { for(int i = head[u] ; i ; i = E[i].next) { int v = E[i].to; if(v != fa) { dfs(v,u); } } mask[u] = 0; vector<int> vec; for(int i = head[u] ; i ; i = E[i].next) { int v = E[i].to; if(v != fa) { mask[u] |= mask[v]; vec.pb(mask[v]); } } int t = 0; for(int i = 0 ; i <= 20 ; ++i) { if(mask[u] >> i & 1) { if(t == i) ++t; int cnt = 0; for(auto k : vec) { if(k >> i & 1) ++cnt; } if(cnt > 1) t = max(t,i + 1); } } mask[u] |= (1 << t); ans = max(ans,t); for(int i = 0 ; i < t ; ++i) { if(mask[u] >> i & 1) mask[u] ^= (1 << i); } return ; } void Solve() { read(N); int a,b; for(int i = 1 ; i < N ; ++i) { read(a);read(b);add(a,b);add(b,a); } dfs(1,0); out(ans);enter; } int main() { #ifdef ivorysi freopen("f1.in","r",stdin); #endif Solve(); return 0; }
大意:有N个0和M个1,每次选择K个数而后把它们的平均数写在上面,保证最后只剩下一个数,问这一个数有几种状况it
就是这个数是一个K进制数,而后转成十进制,设操做次数是c,分母就都是\(K^{c}\)io
而后咱们只关心这个K进制数,从高位到低位枚举每一位的值,而后看看这一行须要几个1,几个0,是否在这里封死(就是每一层我只填K - 1个,封死的那一个须要填K个)为了避免重不漏,我要求封死的时候这个地方填了数,每次封死的时候能够统计,须要剩下的1和剩下的0都是K - 1的倍数
我程序里好像N当1,M当0了,不太小问题,由于反过来问题是等价的
#include <bits/stdc++.h> #define fi first #define se second #define pii pair<int,int> #define mp make_pair #define pb push_back #define space putchar(' ') #define enter putchar('\n') #define eps 1e-10 #define MAXN 100005 //#define ivorysi using namespace std; typedef long long int64; typedef unsigned int u32; typedef double db; template<class T> void read(T &res) { res = 0;T f = 1;char c = getchar(); while(c < '0' || c > '9') { if(c == '-') f = -1; c = getchar(); } while(c >= '0' && c <= '9') { res = res * 10 +c - '0'; c = getchar(); } res *= f; } template<class T> void out(T x) { if(x < 0) {x = -x;putchar('-');} if(x >= 10) { out(x / 10); } putchar('0' + x % 10); } const int MOD = 1000000007; int N,M,K; int dp[4005][2005]; int inc(int a,int b) { return a + b >= MOD ? a + b - MOD : a + b; } int mul(int a,int b) { return 1LL * a * b % MOD; } void update(int &x,int y) { x = inc(x,y); } void Solve() { read(N);read(M);read(K); if(!M || !N) {puts("1");return;} int t = (N + M - 1) / (K - 1) - 1; dp[t + 1][0] = 1; int ans = 0; for(int i = t ; i >= 0 ; --i) { for(int k = 0 ; k <= M ; ++k) { for(int j = 0 ; j < K - 1 ; ++j) { if(j > k) break; update(dp[i][k],dp[i + 1][k - j]); } if(k != M) { int o = (t - i + 1) * (K - 1) - k; if((M - k - 1) % (K - 1) == 0 && N >= o && (N - o) % (K - 1) == 0) { update(ans,dp[i][k]); } } if(k >= (K - 1)) update(dp[i][k],dp[i + 1][k - (K - 1)]); } } out(ans);enter; } int main() { #ifdef ivorysi freopen("f1.in","r",stdin); #endif Solve(); return 0; }