Editorial for Tam giác vàng
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 <map> using namespace std; int main() { int n, x[1010], y[1010], ans = 0; cin >> n; for (int i = 0; i < n; i++) cin >> x[i] >> y[i]; for (int i = 0; i < n; i++) { map <long long,int> d; for (int j = 0; j < n; j++) ans += d[1LL* (x[i] - x[j]) * (x[i] - x[j]) + 1LL * (y[i] - y[j]) * (y[i] - y[j])]++; } cout << ans << endl; }
Code mẫu của happyboy99x
#include<cstdio> #include<algorithm> using namespace std; const int N = 1000 + 2; pair<long long, int> d[N][N]; long long sd[N][N]; int x[N], y[N], n; long long sqr(long long x) { return x * x; } long long dis(int u, int v) { return sqr(x[u] - x[v]) + sqr(y[u] - y[v]); } int main() { scanf("%d", &n); for(int i = 0; i < n; ++i) scanf("%d%d",x+i,y+i); for(int i = 0; i < n; ++i) { for(int j = 0; j < n; ++j) d[i][j] = make_pair(dis(i, j), j), sd[i][j] = d[i][j].first; sort(d[i], d[i]+n); } int res = 0; for(int i = 0; i < n; ++i) for(int b = 0, e = 1; e <= n; ++e) if(d[i][e].first != d[i][b].first) { for(int u = b; u < e; ++u) for(int v = u+1; v < e; ++v) res += sd[d[i][u].second][d[i][v].second] != d[i][u].first; b = e; } printf("%d\n", res); return 0; }
Code mẫu của ladpro98
program spoj_triland; uses math; const fi=''; var x,y:array[1..1111] of int64; f:array[1..1111] of int64; n,i,j,c,t:longint; inp:text; res:int64; procedure swap(i,j:longint); var t:int64; begin t:=f[i]; f[i]:=f[j]; f[j]:=t; end; procedure sort(l,r:longint); var pivot:int64; i,j:longint; begin if l>=r then exit; pivot:=f[random(r-l+1)+l]; i:=l;j:=r; repeat while f[i]<pivot do inc(i); while f[j]>pivot do dec(j); if i<=j then begin if i<j then swap(i,j); inc(i); dec(j); end; until i>j; sort(l,j); sort(i,r); end; procedure input; var i:longint; begin assign(inp,fi); reset(inp); readln(inp,n); for i:=1 to n do begin readln(inp,x[i],y[i]); end; close(inp); end; begin res:=0; input; for i:=1 to n do begin t:=1; for j:=1 to i-1 do begin f[t]:=sqr(x[i]-x[j])+sqr(y[i]-y[j]); inc(t); end; for j:=i+1 to n do begin f[t]:=sqr(x[i]-x[j])+sqr(y[i]-y[j]); inc(t); end; t:=n-1; sort(1,t); j:=1; while j<=t do begin c:=1; while (f[j]=f[j+1]) do begin inc(c); inc(j); end; inc(res,(c*(c-1)) div 2); inc(j); end; end; write(res); end.
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); struct Point { ll x, y; Point(ll x = 0, ll y = 0) : x(x), y(y) {} Point operator + (Point a) { return Point(x+a.x, y+a.y); } Point operator - (Point a) { return Point(x-a.x, y-a.y); } void read() { int _x, _y; scanf("%d%d", &_x, &_y); x = _x; y = _y; } ll sqlen() { return x*x + y*y; } } a[1011]; ll x[1011]; int main() { int n; scanf("%d", &n); FOR(i,1,n) a[i].read(); long long res = 0; FOR(i,1,n) { FOR(j,1,n) x[j] = (a[i] - a[j]).sqlen(); sort(x+1, x+n+1); int j = 2; FOR(i,2,n) { while (j < n && x[j+1] == x[i]) ++j; res += j - i; } } cout << res << endl; return 0; }
Code mẫu của hieult
#include <set> #include <map> #include <list> #include <cmath> #include <queue> #include <stack> #include <cstdio> #include <string> #include <vector> #include <cstdlib> #include <cstring> #include <sstream> #include <iomanip> #include <iostream> #include <algorithm> #include <ctime> #include <deque> #include <bitset> #include <cctype> #include <utility> #include <cassert> using namespace std; typedef long long ll; typedef double ld; typedef unsigned int ui; typedef unsigned long long ull; #define Rep(i,n) for(int i = 0; i < (n); ++i) #define Repd(i,n) for(int i = (n)-1; i >= 0; --i) #define For(i,a,b) for(int i = (a); i <= (b); ++i) #define Ford(i,a,b) for(int 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)) 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> 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> 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 = (int) 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; } typedef pair<int, int> II; const ld PI = acos(-1.0); const ld eps = 1e-9; const int dr[] = {0, +1, 0, -1}; const int dc[] = {+1, 0, -1, 0}; const int inf = (int)1e9 + 5; const ll linf = (ll)1e16 + 5; const ll mod = (ll)1e9 + 7; #define maxn 1005 int n; ll x[maxn], y[maxn], f[maxn][maxn]; int main() { // freopen("in.txt", "r", stdin); scanf("%d", &n); For(i, 1, n) cin >> x[i] >> y[i]; For(i, 1, n) For(j, 1, n) f[i][j] = sqr(x[i] - x[j]) + sqr(y[i] - y[j]); int res = 0; For(i, 1, n) { vector<ll> V; For(j, 1, n) V.pb(f[i][j]); V.pb(-1); V.pb(linf); sort(all(V)); int run = 1; Rep(i, sz(V) - 1){ if(V[i] == V[i + 1]) run++; else run = 1; res += run - 1; } } cout << res; return 0; }
Code mẫu của skyvn97
#include<stdio.h> #define MAX 2000 typedef unsigned long long ull; struct point { ull x; ull y; }; struct distance { ull dis; ull n; }; point a[MAX]; ull dist[MAX][MAX]; distance dsort[MAX][MAX]; ull n,res; void merge(distance a[],int left,int mid,int right) { distance b[MAX]; distance c[MAX]; int i,j,k; for (i=left;i<=mid;i=i+1) b[i-left+1]=a[i]; for (i=mid+1;i<=right;i=i+1) c[i-mid]=a[i]; j=1; k=1; for (i=left;i<=right;i=i+1) { if (j>mid-left+1) { a[i]=c[k]; k=k+1; continue; } if (k>right-mid) { a[i]=b[j]; j=j+1; continue; } if (b[j].dis<c[k].dis) { a[i]=b[j]; j=j+1; continue; } a[i]=c[k]; k=k+1; } } void mergesort(distance a[],int left,int right) { if (left>=right) return; int mid=(left+right)/2; mergesort(a,left,mid); mergesort(a,mid+1,right); merge(a,left,mid,right); } void init(void) { ull i,j,k; scanf("%llu",&n); for (i=1;i<=n;i=i+1) { scanf("%llu",&a[i].x); scanf("%llu",&a[i].y); } for (i=1;i<=n;i=i+1) for (j=1;j<=n;j=j+1) { dist[i][j]=(a[i].x-a[j].x)*(a[i].x-a[j].x)+(a[i].y-a[j].y)*(a[i].y-a[j].y); dsort[i][j].dis=dist[i][j]; dsort[i][j].n=j; } ull res=0; for (i=1;i<=n;i=i+1) { mergesort(dsort[i],1,n); for (j=1;j<n;j=j+1) for (k=j+1;k<=n;k=k+1) { if (dsort[i][j].dis<dsort[i][k].dis) break; if (dist[dsort[i][j].n][dsort[i][k].n]!=dsort[i][j].dis) res++; } } printf("%llu",res); } int main(void) { init(); return 0; }
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