HDU 6206 Apple（高精度C++）

题意：给你三个点，保证不再同一条直线上，再给你一点，问你是否在这三个点形成的圆外。

思路：就是求出三个点外接圆的圆心和半径判断下。

已知三点坐标，求外接圆圆心坐标与半径。

#include<string>#include<iostream>#include<iosfwd>#include<cmath>#include<cstring>#include<stdlib.h>#include<stdio.h>#include<cstring>#define MAX_L 2005 //最大长度，可以修改using namespace std;#define max_n 100000000//因为结果可能不是整数，把小数部分去掉class bign{public:    int len, s[MAX_L];//数的长度，记录数组//构造函数    bign();    bign(const char*);    bign(int);    bool sign;//符号 1正数 0负数    string toStr() const;//转化为字符串，主要是便于输出    friend istream& operator>>(istream &,bign &);//重载输入流    friend ostream& operator<<(ostream &,bign &);//重载输出流//重载复制    bign operator=(const char*);    bign operator=(int);    bign operator=(const string);//重载各种比较    bool operator>(const bign &) const;    bool operator>=(const bign &) const;    bool operator<(const bign &) const;    bool operator<=(const bign &) const;    bool operator==(const bign &) const;    bool operator!=(const bign &) const;//重载四则运算    bign operator+(const bign &) const;    bign operator++();    bign operator++(int);    bign operator+=(const bign&);    bign operator-(const bign &) const;    bign operator--();    bign operator--(int);    bign operator-=(const bign&);    bign operator*(const bign &)const;    bign operator*(const int num)const;    bign operator*=(const bign&);    bign operator/(const bign&)const;    bign operator/=(const bign&);//四则运算的衍生运算    bign operator%(const bign&)const;//取模（余数）    bign factorial()const;//阶乘    bign Sqrt()const;//整数开根（向下取整）    bign pow(const bign&)const;//次方//一些乱乱的函数    void clean();    ~bign();};#define max(a,b) a>b ? a : b#define min(a,b) a<b ? a : bbign::bign(){    memset(s, 0, sizeof(s));    len = 1;    sign = 1;}bign::bign(const char *num){    *this = num;}bign::bign(int num){    *this = num;}string bign::toStr() const{    string res;    res = "";    for (int i = 0; i < len; i++)        res = (char)(s[i] + '0') + res;    if (res == "")        res = "0";    if (!sign&&res != "0")        res = "-" + res;    return res;}istream &operator>>(istream &in, bign &num){    string str;    in>>str;    num=str;    return in;}ostream &operator<<(ostream &out, bign &num){    out<<num.toStr();    return out;}bign bign::operator=(const char *num){    memset(s, 0, sizeof(s));    char a[MAX_L] = "";    if (num[0] != '-')        strcpy(a, num);    else        for (int i = 1; i < strlen(num); i++)            a[i - 1] = num[i];    sign = !(num[0] == '-');    len = strlen(a);    for (int i = 0; i < strlen(a); i++)        s[i] = a[len - i - 1] - 48;    return *this;}bign bign::operator=(int num){    char temp[MAX_L];    sprintf(temp, "%d", num);    *this = temp;    return *this;}bign bign::operator=(const string num){    const char *tmp;    tmp = num.c_str();    *this = tmp;    return *this;}bool bign::operator<(const bign &num) const{    if (sign^num.sign)        return num.sign;    if (len != num.len)        return len < num.len;    for (int i = len - 1; i >= 0; i--)        if (s[i] != num.s[i])            return sign ? (s[i] < num.s[i]) : (!(s[i] < num.s[i]));    return !sign;}bool bign::operator>(const bign&num)const{    return num < *this;}bool bign::operator<=(const bign&num)const{    return !(*this>num);}bool bign::operator>=(const bign&num)const{    return !(*this<num);}bool bign::operator!=(const bign&num)const{    return *this > num || *this < num;}bool bign::operator==(const bign&num)const{    return !(num != *this);}bign bign::operator+(const bign &num) const{    if (sign^num.sign)    {        bign tmp = sign ? num : *this;        tmp.sign = 1;        return sign ? *this - tmp : num - tmp;    }    bign result;    result.len = 0;    int temp = 0;    for (int i = 0; temp || i < (max(len, num.len)); i++)    {        int t = s[i] + num.s[i] + temp;        result.s[result.len++] = t % 10;        temp = t / 10;    }    result.sign = sign;    return result;}bign bign::operator++(){    *this = *this + 1;    return *this;}bign bign::operator++(int){    bign old = *this;    ++(*this);    return old;}bign bign::operator+=(const bign &num){    *this = *this + num;    return *this;}bign bign::operator-(const bign &num) const{    bign b=num,a=*this;    if (!num.sign && !sign)    {        b.sign=1;        a.sign=1;        return b-a;    }    if (!b.sign)    {        b.sign=1;        return a+b;    }    if (!a.sign)    {        a.sign=1;        b=bign(0)-(a+b);        return b;    }    if (a<b)    {        bign c=(b-a);        c.sign=false;        return c;    }    bign result;    result.len = 0;    for (int i = 0, g = 0; i < a.len; i++)    {        int x = a.s[i] - g;        if (i < b.len) x -= b.s[i];        if (x >= 0) g = 0;        else        {            g = 1;            x += 10;        }        result.s[result.len++] = x;    }    result.clean();    return result;}bign bign::operator * (const bign &num)const{    bign result;    result.len = len + num.len;    for (int i = 0; i < len; i++)        for (int j = 0; j < num.len; j++)            result.s[i + j] += s[i] * num.s[j];    for (int i = 0; i < result.len; i++)    {        result.s[i + 1] += result.s[i] / 10;        result.s[i] %= 10;    }    result.clean();    result.sign = !(sign^num.sign);    return result;}bign bign::operator*(const int num)const{    bign x = num;    bign z = *this;    return x*z;}bign bign::operator*=(const bign&num){    *this = *this * num;    return *this;}bign bign::operator /(const bign&num)const{    bign ans;    ans.len = len - num.len + 1;    if (ans.len < 0)    {        ans.len = 1;        return ans;    }    bign divisor = *this, divid = num;    divisor.sign = divid.sign = 1;    int k = ans.len - 1;    int j = len - 1;    while (k >= 0)    {        while (divisor.s[j] == 0) j--;        if (k > j) k = j;        char z[MAX_L];        memset(z, 0, sizeof(z));        for (int i = j; i >= k; i--)            z[j - i] = divisor.s[i] + '0';        bign dividend = z;        if (dividend < divid) { k--; continue; }        int key = 0;        while (divid*key <= dividend) key++;        key--;        ans.s[k] = key;        bign temp = divid*key;        for (int i = 0; i < k; i++)            temp = temp * 10;        divisor = divisor - temp;        k--;    }    ans.clean();    ans.sign = !(sign^num.sign);    return ans;}bign bign::operator/=(const bign&num){    *this = *this / num;    return *this;}bign bign::operator%(const bign& num)const{    bign a = *this, b = num;    a.sign = b.sign = 1;    bign result, temp = a / b*b;    result = a - temp;    result.sign = sign;    return result;}bign bign::pow(const bign& num)const{    bign result = 1;    for (bign i = 0; i < num; i++)        result = result*(*this);    return result;}bign bign::factorial()const{    bign result = 1;    for (bign i = 1; i <= *this; i++)        result *= i;    return result;}void bign::clean(){    if (len == 0) len++;    while (len > 1 && s[len - 1] == '\0')        len--;}bign bign::Sqrt()const{    if(*this<0)return -1;    if(*this<=1)return *this;    bign l=0,r=*this,mid;    while(r-l>1)    {        mid=(l+r)/2;        if(mid*mid>*this)            r=mid;        else            l=mid;    }    return l;}bign::~bign(){}int main() {bign x,y,x1,x2,x3,y1,y2,y3,x4,y4;bign a,b,c,d,e,f;bign ling=0;int t;bign dis;bign tes;cin>>t;while(t--){cin>>x1>>y1>>x2>>y2>>x3>>y3>>x4>>y4;x1=x1*max_n;y1=y1*max_n;x2=x2*max_n;y2=y2*max_n;y3=y3*max_n;x3=x3*max_n;x4=x4*max_n;y4=y4*max_n;a=x1-x2;b=y1-y2;c=x1-x3;d=y1-y3;e=(x1*x1-x2*x2-y2*y2+y1*y1)/2;f=(x1*x1-x3*x3-y3*y3+y1*y1)/2;x= (d*e-b*f)/(b*c-a*d);y= (a*f-c*e)/(b*c-a*d);dis=(x+x1)*(x+x1)+(y+y1)*(y+y1);tes=(x+x4)*(x+x4)+(y+y4)*(y+y4);if(dis<tes)printf("Accepted\n");elseprintf("Rejected\n");}  return 0;}