Editorial for Biến đổi hoán vị
Remember to use this editorial only when stuck, and not to copy-paste code from it. Please be respectful to the problem author and editorialist.
Submitting an official solution before solving the problem yourself is a bannable offence.
Submitting an official solution before solving the problem yourself is a bannable offence.
Lưu ý: Các code mẫu dưới đây chỉ mang tính tham khảo và có thể không AC được bài tập này
Code mẫu của flashmt
#include <iostream> #include <algorithm> #include <cstdio> using namespace std; int n,q,a[100100],p[100100],d[100100]; int main() { cin >> n >> q; for (int i=1;i<=n;i++) scanf("%d",p+i); for (int i=1;i<=n;i++) { int j=i; while (!d[j]) d[j]=i, j=p[j]; } for (int i=2;i<=n;i++) if (d[i]==d[1]) d[i]=d[2]; d[1]=d[2]; int x,y; while (q--) { scanf("%d%d",&x,&y); puts(d[x]==d[y]?"Yes":"No"); } }
Code mẫu của ladpro98
#include <bits/stdc++.h> using namespace std; const int N = 100005; int p[N]; int cycle[N]; int n, m, nCycle; int main() { ios::sync_with_stdio(0); cin.tie(0); cin >> n >> m; for (int i = 1; i <= n; ++i) cin >> p[i]; for (int i = 1; i <= n; ++i) if (!cycle[i]) { ++nCycle; for (int j = i; !cycle[j]; j = p[j]) cycle[j] = nCycle; } int u, v; while (m--) { cin >> u >> v; bool YES = cycle[u] == cycle[v]; YES |= cycle[u] == cycle[1] && cycle[v] == cycle[2]; YES |= cycle[u] == cycle[2] && cycle[v] == cycle[1]; cout << (YES ? "Yes\n" : "No\n"); } return 0; }
Code mẫu của RR
#include <sstream> #include <iomanip> #include <iostream> #include <cstdio> #include <cstring> #include <cstdlib> #include <cmath> #include <algorithm> #include <vector> #include <set> #include <map> #include <stack> #include <queue> #include <string> #include <deque> #include <complex> #define FOR(i,a,b) for(int i=(a),_b=(b); i<=_b; i++) #define FORD(i,a,b) for(int i=(a),_b=(b); i>=_b; i--) #define REP(i,a) for(int i=0,_a=(a); i<_a; i++) #define FORN(i,a,b) for(int i=(a),_b=(b);i<_b;i++) #define DOWN(i,a,b) for(int i=a,_b=(b);i>=_b;i--) #define SET(a,v) memset(a,v,sizeof(a)) #define sqr(x) ((x)*(x)) #define ll long long #define F first #define S second #define PB push_back #define MP make_pair #define DEBUG(x) cout << #x << " = "; cout << x << endl; #define PR(a,n) cout << #a << " = "; FOR(_,1,n) cout << a[_] << ' '; cout << endl; #define PR0(a,n) cout << #a << " = "; REP(_,n) cout << a[_] << ' '; cout << endl; using namespace std; //Buffer reading int INP,AM,REACHEOF; #define BUFSIZE (1<<12) char BUF[BUFSIZE+1], *inp=BUF; #define GETCHAR(INP) { \ if(!*inp) { \ if (REACHEOF) return 0;\ memset(BUF,0,sizeof BUF);\ int inpzzz = fread(BUF,1,BUFSIZE,stdin);\ if (inpzzz != BUFSIZE) REACHEOF = true;\ inp=BUF; \ } \ INP=*inp++; \ } #define DIG(a) (((a)>='0')&&((a)<='9')) #define GN(j) { \ AM=0;\ GETCHAR(INP); while(!DIG(INP) && INP!='-') GETCHAR(INP);\ if (INP=='-') {AM=1;GETCHAR(INP);} \ j=INP-'0'; GETCHAR(INP); \ while(DIG(INP)){j=10*j+(INP-'0');GETCHAR(INP);} \ if (AM) j=-j;\ } //End of buffer reading const long double PI = acos((long double) -1.0); int n, m, lab[100111]; int getRoot(int u) { if (lab[u] < 0) return u; return lab[u] = getRoot(lab[u]); } void merge(int u, int v) { u = getRoot(u); v = getRoot(v); if (u == v) return ; if (lab[u] < lab[v]) { lab[u] += lab[v]; lab[v] = u; } else { lab[v] += lab[u]; lab[u] = v; } } int main() { GN(n); GN(m); FOR(i,1,n) lab[i] = -1; int to; FOR(i,1,n) { GN(to); merge(i, to); } merge(1, 2); while (m--) { int u, v; GN(u); GN(v); if (getRoot(u) == getRoot(v)) puts("Yes"); else puts("No"); } return 0; }
Code mẫu của hieult
#include <set> #include <map> #include <list> #include <cmath> #include <ctime> #include <deque> #include <queue> #include <stack> #include <bitset> #include <cctype> #include <cstdio> #include <string> #include <vector> #include <cassert> #include <cstdlib> #include <cstring> #include <sstream> #include <iomanip> #include <iostream> #include <algorithm> using namespace std; typedef long long ll; typedef long double ld; //typedef double ld; typedef unsigned int ui; typedef unsigned long long ull; #define Rep(i,n) for(__typeof(n) i = 0; i < (n); ++i) #define Repd(i,n) for(__typeof(n) i = (n)-1; i >= 0; --i) #define For(i,a,b) for(__typeof(b) i = (a); i <= (b); ++i) #define Ford(i,a,b) for(__typeof(a) i = (a); i >= (b); --i) #define Fit(i,v) for(__typeof((v).begin()) i = (v).begin(); i != (v).end(); ++i) #define Fitd(i,v) for(__typeof((v).rbegin()) i = (v).rbegin(); i != (v).rend(); ++i) #define mp make_pair #define pb push_back #define fi first #define se second #define sz(a) ((int)(a).size()) #define all(a) (a).begin(), (a).end() #define ms(a,x) memset(a, x, sizeof(a)) #define nl puts("") #define sp printf(" ") #define ok puts("ok") //#include <conio.h> template<class F, class T> T convert(F a, int p = -1) { stringstream ss; if (p >= 0) ss << fixed << setprecision(p); ss << a; T r; ss >> r; return r; } template<class T> void db(T a, int p = -1) { if (p >= 0) cout << fixed << setprecision(p); cout << a << " "; } template<class T> T gcd(T a, T b) { T r; while (b != 0) { r = a % b; a = b; b = r; } return a; } template<class T> T lcm(T a, T b) { return a / gcd(a, b) * b; } template<class T> T sqr(T x) { return x * x; } template<class T> T cube(T x) { return x * x * x; } template<class T> struct Triple { T x, y, z; Triple() {} Triple(T _x, T _y, T _z) : x(_x), y(_y), z(_z) {} }; template<class T> Triple<T> euclid(T a, T b) { if (b == 0) return Triple<T>(1, 0, a); Triple<T> r = euclid(b, a % b); return Triple<T>(r.y, r.x - a / b * r.y, r.z); } template<class T> int getbit(T s, int i) { return (s >> i) & 1; } template<class T> T onbit(T s, int i) { return s | (T(1) << i); } template<class T> T offbit(T s, int i) { return s & (~(T(1) << i)); } template<class T> int cntbit(T s) { return s == 0 ? 0 : cntbit(s >> 1) + (s & 1); } const int bfsz = 1 << 16; char bf[bfsz + 5]; int rsz = 0;int ptr = 0; char gc() { if (rsz <= 0) { ptr = 0; rsz = fread(bf, 1, bfsz, stdin); if (rsz <= 0) return EOF; } --rsz; return bf[ptr++]; } void ga(char &c) { c = EOF; while (!isalpha(c)) c = gc(); } int gs(char s[]) { int l = 0; char c = gc(); while (isspace(c)) c = gc(); while (c != EOF && !isspace(c)) { s[l++] = c; c = gc(); } s[l] = '\0'; return l; } template<class T> bool gi(T &v) { v = 0; char c = gc(); while (c != EOF && c != '-' && !isdigit(c)) c = gc(); if (c == EOF) return false; bool neg = c == '-'; if (neg) c = gc(); while (isdigit(c)) { v = v * 10 + c - '0'; c = gc(); } if (neg) v = -v; return true; } const double PI = 2 * acos(0); const string months[] = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"}; const int days[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; const int dr[] = {0, 0, -1, +1}; const int dc[] = {-1, +1, 0, 0}; const int inf = (int)1e9 + 5; const ll linf = (ll)1e16 + 5; const double eps = ld(1e-9); const ll mod = 100000007; typedef pair<int, int> II; #define maxn 200005 #define maxv 1005 int n, m, a[maxn], dad[maxn], u, v; int main(){ // freopen("in.txt", "r", stdin); // freopen("out.txt", "w", stdout); scanf("%d %d", &n, &m); ms(dad, 0); For(i, 1, n) scanf("%d", &a[i]); For(i, 1, n) if(!dad[i]){ u = i; dad[u] = (i == 2 ? 1 : i); u = a[u]; while(u != i){ dad[u] = (i == 2 ? 1 : i); u = a[u]; } } Rep(run, m){ scanf("%d %d", &u, &v); if(dad[u] == dad[v]){ printf("Yes\n"); } else printf("No\n"); } return 0; }
Code mẫu của skyvn97
#include<stack> #include<cstdio> #include<cstring> #define MAX 100100 using namespace std; struct vector { int d[3]; int sz; vector(){} void clear(void) { sz=0; } int size(void) const { return (sz); } int operator [] (const int &i) const { return d[i]; } void push_back(const int &val) { sz++; d[sz-1]=val; } }; vector g[MAX]; int n,q,nc,cnt; int p[MAX]; int ncp[MAX]; int low[MAX]; int num[MAX]; bool fr[MAX]; stack<int> st; void init(void) { scanf("%d",&n); scanf("%d",&q); int i; for (i=1;i<=n;i=i+1) { scanf("%d",&p[i]); g[i].clear(); } for (i=1;i<=n;i=i+1) { if (i==1 && p[i]==2) continue; if (i==2 && p[i]==1) continue; if (i==p[i]) continue; g[i].push_back(p[i]); } g[1].push_back(2); g[2].push_back(1); } int min(const int &x,const int &y) { if (x<y) return (x); else return (y); } void visit(const int &u) { int i,v; cnt++; num[u]=cnt; low[u]=cnt; st.push(u); for (i=0;i<g[u].size();i=i+1) { v=g[u][i]; if (fr[v]) { if (num[v]>0) low[u]=min(low[u],num[v]); else { visit(v); low[u]=min(low[u],low[v]); } } } if (low[u]==num[u]) { nc++; do { v=st.top();st.pop(); fr[v]=false; ncp[v]=nc; } while (v!=u); } } void tarjan(void) { memset(low,0,sizeof low); memset(num,0,sizeof num); memset(fr,true,sizeof fr); cnt=0;nc=0; int i; for (i=1;i<=n;i=i+1) if (num[i]==0) visit(i); } void answer(void) { int i,u,v; for (i=1;i<=q;i=i+1) { scanf("%d",&u); scanf("%d",&v); if (ncp[u]==ncp[v]) printf("Yes\n"); else printf("No\n"); } } int main(void) { init(); tarjan(); answer(); return 0; }
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