從後往前遞推便可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; }
從葉子往根遞推,在一個節點合併的時候從小到大合併,每次是當前值和合並的值最大值+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; }
\(dp[i][j]\)表示第一個集合最後一個是\(A[i]\),第二個集合最後一個是\(A[j]\),假如dp到第k個數,這二維必然有一個是k - 1,線段樹優化轉移便可優化
#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:一個點的數值是1,每次能夠選擇一箇中心點和周圍最大價值爲k的樹合成一個k + 1的樹,給定一棵樹,問最小值是多少ui
其實就是轉化成一個標號,若是這個點在k的樹中做爲中心點被選了,那麼這個點標號爲kspa
而後要求兩個相同的數之間必須有一個比他們都大的數code
答案個數不超過log N,因此把每一個子樹裏不能選的數壓成一個二進制數,父親不能選的是全部子樹不能選的並集,並且子樹中如有兩個數都不能選,則選擇的數必須大於這個數ip
而後該點若選了t,比t小的值均可以標記爲可選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個0和M個1,每次選擇K個數而後把它們的平均數寫在上面,保證最後只剩下一個數,問這一個數有幾種狀況it
就是這個數是一個K進制數,而後轉成十進制,設操做次數是c,分母就都是\(K^{c}\)io
而後咱們只關心這個K進制數,從高位到低位枚舉每一位的值,而後看看這一行須要幾個1,幾個0,是否在這裏封死(就是每一層我只填K - 1個,封死的那一個須要填K個)爲了避免重不漏,我要求封死的時候這個地方填了數,每次封死的時候能夠統計,須要剩下的1和剩下的0都是K - 1的倍數
我程序裏好像N當1,M當0了,不太小問題,由於反過來問題是等價的
#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; }