C++ Poly::push_back方法代码示例

std::vector<cdouble >
laguerre(Poly p, const double tol) {
    std::vector<cdouble > solutions;
    //std::cout << "p = " << p << " = ";
    while(p.size() > 1)
    {
        double x0 = 0;
        bool quad_root = false;
        cdouble sol = laguerre_internal_complex(p, x0, tol, quad_root);
        //if(abs(sol) > 1) break;
        Poly dvs;
        if(quad_root) {
            dvs.push_back((sol*conj(sol)).real());
            dvs.push_back(-(sol + conj(sol)).real());
            dvs.push_back(1.0);
            //std::cout << "(" <<  dvs << ")";
            //solutions.push_back(sol);
            //solutions.push_back(conj(sol));
        } else {
            //std::cout << sol << std::endl;
            dvs.push_back(-sol.real());
            dvs.push_back(1.0);
            solutions.push_back(sol);
            //std::cout << "(" <<  dvs << ")";
        }
        Poly r;
        p = divide(p, dvs, r);
        //std::cout << r << std::endl;
    }
    return solutions;
}

vector<Poly> triangulate( const Poly &p ){
	vector<Poly> res;
	int n = p.size();
	vector<int> l, r;
	for( int i = 0; i < n; i++){
		l.push_back( ( i - 1 + n) % n );
		r.push_back( ( i + 1) % n );
	}
	int i = n - 1, cagao = 0;
	while( res.size() < n - 2 ){
		if ( cagao >= n ) return vector<Poly>();
		i = r[i];
		Poly tmp;
		tmp.push_back( p[l[i]] );
		tmp.push_back( p[i] );
		tmp.push_back( p[r[i]] );

		if ( can( tmp, p , l[i], i , r[i] ) ){
			res.push_back( tmp );
			l[ r[i] ] = l[i];
			r[ l[i] ] = r[i];
			cagao = 0;
		}else cagao++;
	}
	return res;
}

int main(){
	int runs;
	scanf("%d",&runs );
	while( runs-- ){
		int n;
		scanf("%d",&n);
		Poly R;
		double S = 0;
		while( n--) {
			double w, h, a, x , y;
			Point c;
			scanf("%lf%lf%lf%lf%lf", &c.x, &c.y, &w,&h,&a );
			a = a * M_PI / 180.0;
			S += w * h ;

			w /= 2;
			h /= 2;

			R.push_back( c + rot( Point( w, h ) , a ) );
			R.push_back( c + rot( Point( w, -h ) , a ) );
			R.push_back( c + rot( Point( -w, h ) , a ) );
			R.push_back( c + rot( Point( -w, -h ) , a ) );

		}
		double Total = area( convexHull( R ) );
		printf("%.1lf %%\n", S/Total*100 );

	}

	return 0;
}

// debe ser antihorario
vector<Poly> triangulate( const Poly &p ){
	vector<Poly> res;
	int n = p.size();
	vector<int> l, r;
	for( int i = 0; i < n; i++){
		l.push_back( ( i - 1 + n) % n );
		r.push_back( ( i + 1) % n ); // crea una lista doblemente enlazada
	}
	int i = n - 1, cagao = 0;
	while( res.size() < n - 2 ){
		if ( cagao >= n ) return vector<Poly>();
		i = r[i]; // avanza tipo un i++
		Poly tmp; 
		tmp.push_back( p[l[i]] );
		tmp.push_back( p[i] );
		tmp.push_back( p[r[i]] ); // crea un triangulo

		if ( can( tmp, p , l[i], i , r[i] ) ){ // checa si sirve
			res.push_back( tmp ); // guardamos la solucion
			l[ r[i] ] = l[i];
			r[ l[i] ] = r[i]; // con estas dos operaciones en O(1) borramos el punto del "medio" del triangulo
			cagao = 0; // no fallo
		}else cagao++; // se fue al carajo
	}
	return res;
}

int main(){

	int runs;
	cin >> runs;
	for( int r = 1; r <= runs; r++){
		string s;
		cin >> s;
		Point cur( 0, 0 );
		Poly p;
		for( int i = 0; i < s.size(); i++){
			switch(s[i]){
				case 'D':
					cur = Point( cur.x - 1 , cur. y);
					p.push_back( cur ) ;
					break;
				case 'U':
					cur = Point( cur.x + 1 , cur. y);
					p.push_back( cur ) ;
					break;
				case 'R':
					cur = Point( cur.x , cur. y + 1);
					p.push_back( cur ) ;
					break;
				case 'L':
					cur = Point( cur.x , cur. y - 1);
					p.push_back( cur ) ;
					break;
			
			}
		}
		printf("case %d: %.lf\n", r, area( p ));
	}

	return 0;
}

Poly integral(Poly const & p) {
    Poly result;
    
    result.reserve(p.size()+1);
    result.push_back(0); // arbitrary const
    for(unsigned i = 0; i < p.size(); i++) {
        result.push_back(p[i]/(i+1));
    }
    return result;

}

Poly readTri() {
	Poly ret;
	for (int i = 0; i < 3; ++i) {
		Point p;
		cin >> p.x >> p.y;
		ret.push_back(p);
	}
	return convexHull(ret);
}

Poly derivative(Poly const & p) {
    Poly result;
    
    if(p.size() <= 1)
        return Poly(0);
    result.reserve(p.size()-1);
    for(unsigned i = 1; i < p.size(); i++) {
        result.push_back(i*p[i]);
    }
    return result;
}

int main(){
	char buff[ 50 ];
	int runs;
	scanf("%d\n",&runs);
	bool t = 0;
	while( runs--){
		if ( t ) putchar( 10 );
		t = 1;
		Poly p;
		while( gets(buff) && buff[0] ){
			int x, y;
			sscanf( buff, "%d %d",&x,&y);
			p.push_back( Point ( x, y  ));
		}
		printf( "%d\n", lining( p ) );
	}

	return 0;
}

int main(){

	int runs;
	scanf("%d",&runs);
	while( runs--){
		int n;
		scanf("%d",&n);
		int R[ n + 1 ];
		Poly p;
		for( int i = 0; i < n; i++){
			int x , y;
			scanf("%d %d",&x,&y);
			p.push_back( Point( x, y ) );
		}
		sort( p.begin(), p.end() );
		for( int i = 0; i < n ; i++ ) {
			p[i].id = i ;
			R[i] = i + 1;
		}
		
		int sig[ n + 1 ];
		int id = 0;
		for( int i = 0; i < n; i++){
			int id = i + 1;
			bool cagao = false;
			for( int j = i + 1; j < n; j++){
				if ( p[i].y < p[j].y ) cagao = true;
				if ( p[j].y > p[id].y ) id = j;
			}
			if ( !cagao ) {
				sig[i] = id;
			}else{
				sig[i] = -1;
			}
		}
		Poly h;
		for( int i = 0; i < n; i++){
			if ( sig[i] != -1 ){
				for( int pos = i ; pos != n; pos = sig[pos] ){
					h.push_back( p[pos] );
				}
				break;
			}
		}
		int s = 0;
		if ( h[0].y < h[1].y) s++;
		double res = 0.0;
		for( int i = s; i < h.size()-1 ; i++){
			// a = h[i], b = h[i+1], c es la interseccion de la recta a,R[a].id
			// con el vector b(b.x+5, b.y)
			Recta ac ( h[i+1], Point( h[i+1].x+5, h[i+1].y ));
			Recta cb ( h[i], p[ R[ h[i].id ] ] );
			bool paralelas = false;
			Point c = ac.intersect( cb ,paralelas );
			res += dist( h[i], c );
		}
		printf("%.2lf\n", res );
		
	}

	return 0;
}

// Generate from (x+1)^k to (x+1)^(k+1).
void next(Poly& B) {
    for(int i = B.size() - 1; i >= 1; --i)
        B[i] += B[i-1];
    B.push_back(1);
}