诚邀dalao玩找不同

求调，其实也不用大佬动脑子，找不同就行了，因为改的跟大佬的代码几乎一模一样了。

不是eps的问题

WA:

#include <cstdio>
#include <cstring>
#include <set>
#include <algorithm>
#include <cmath>
#include <map>

using namespace std;
#define pow2(x) ((x) * (x))
#define ld long double
const ld cc = cos(0.4);
const ld ss = sin(0.4);
const ld eps = 1e-6;

#define N 5000010

int n;
struct bubble
{
    ld x,y,r;
    bool operator < (const bubble &a)const
    {
        return y < a.y;
    }
}c[N];

struct cmp{bool operator()(int x,int y){return c[x].y<c[y].y;}};

set<int,cmp> st;
set<int,cmp>::iterator it;

struct LINE
{
    ld x;
    int id,op;
    bool operator < (const LINE &a)const
    {
        return x < a.x;
    }
    bool operator > (const LINE &a)const
    {
        return x > a.x;
    }
}line[N];

int linecnt,ans;
map <pair<bubble,bubble>,bool> vis;

int main()
{
    freopen("bubble.in","r",stdin);
    freopen("bubble.out","w",stdout);
    scanf("%d",&n);
    for(int i = 1;i <= n;i++)
    {
        int x,y,z;
        scanf("%d%d%d",&x,&y,&z);
        c[i].x = cc * + ss * y;
        c[i].y = -ss * x + cc * y;
        c[i].r = 1.0 * z;
        line[++linecnt] = (LINE){c[i].x - c[i].r,i,1};
        line[++linecnt] = (LINE){c[i].x + c[i].r,i,-1};
    }
    std::sort(line + 1,line + linecnt + 1);
    for(int i = 1;i <= linecnt;i++)
    {
        if(line[i].op == 1)
        {
            it = st.upper_bound(line[i].id);
            if(it != st.end())
            {
                int pre = *it;
                //printf("%.2LF %.2LF %.2LF : %.2LF %.2LF %.2LF\n",c[pre].x,c[pre].y,c[pre].r,c[line[i].id].x,c[line[i].id].y,c[line[i].id].r);
                //printf("%.8LF ^ 2 + %.8LF ^ 2\n",(c[pre].x - c[line[i].id].x),(c[pre].y - c[line[i].id].y));
                //printf("rdis = %.6LF\n",pow2(c[pre].r + c[line[i].id].r));
                if(fabs(sqrt(pow2(c[pre].x - c[line[i].id].x) + pow2(c[pre].y - c[line[i].id].y)) - (c[pre].r + c[line[i].id].r)) <= eps)
                {
                    if(!vis[make_pair(c[line[i].id],c[pre])])
                    {
                        ans++;
                        vis[make_pair(c[line[i].id],c[pre])] = 1;
                        vis[make_pair(c[pre],c[line[i].id])] = 1;
                    }
                }
            }
            if(it != st.begin())
            {
                it--;
                int suc = *it;
                //printf("%.2LF %.2LF %.2LF : %.2LF %.2LF %.2LF\n",c[suc].x,c[suc].y,c[suc].r,c[line[i].id].x,c[line[i].id].y,c[line[i].id].r);
                //printf("%.8LF ^ 2 + %.8LF ^ 2\n",(c[suc].x - c[line[i].id].x),(c[suc].y - c[line[i].id].y));
                //printf("rdis = %.6LF\n",pow2(c[suc].r + c[line[i].id].r));
                if(fabs(sqrt(pow2(c[suc].x - c[line[i].id].x) + pow2(c[suc].y - c[line[i].id].y)) - (c[suc].r + c[line[i].id].r)) <= eps)
                {
                    if(!vis[make_pair(c[line[i].id],c[suc])])
                    {
                        ans++;
                        vis[make_pair(c[line[i].id],c[suc])] = 1;
                        vis[make_pair(c[suc],c[line[i].id])] = 1;
                    }
                }
            }
            st.insert(line[i].id);
        }
        else
        {
            it = st.find(line[i].id);
            if(it != st.begin()){
                int pre = *--it;
                ++it;
                ++it;
                if(it != st.end())
                {
                    int suc = *it;
                    if(fabs(sqrt(pow2(c[suc].x - c[pre].x) + pow2(c[suc].y - c[line[i].id].y)) - (c[suc].r + c[line[i].id].r)) <= eps)
                    {
                        if(!vis[make_pair(c[pre],c[suc])])
                        {
                            ans++;
                            vis[make_pair(c[pre],c[suc])] = 1;
                            vis[make_pair(c[suc],c[pre])] = 1;
                        }
                    }
                }
                it--;
            }
            st.erase(it);
        }
    }
    printf("%d\n",ans);
    return 0;
}

dalao's AC:

#include<bits/stdc++.h>
using namespace std;

inline int read(){
    int x=0,f=1;
    char ch=getchar();
    while(ch<'0'||ch>'9'){
        if (ch=='-')
            f=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9'){
        x=x*10+ch-'0';
        ch=getchar();
    }
    return x*f;
}

typedef long double ld;
const ld _0=1e-8,_s=std::sin(0.4),_c=std::cos(0.4);
int ans=0;
struct cir{
    ld x,y,r;
}cs[500010];
struct event{
    ld x;
    int id,type;
}es[1000010];
pair<int,int>as[1500050];
int ap=0;
bool operator<(event a,event b){
    return a.x<b.x;
}
#define pow2(x) ((x) * (x))
struct cmp{bool operator()(int x,int y){return cs[x].y<cs[y].y;}};
set<int,cmp>line;
void chk(int a,int b){
    ld x=cs[a].x-cs[b].x,y=cs[a].y-cs[b].y;
    printf("%.8LF ^2 + %.8LF ^ 2\n",x,y);
    printf("%.8LF\n",sqrt(x*x+y*y)-(cs[a].r + cs[b].r));
    if(std::fabs(std::sqrt(x*x+y*y)-cs[a].r-cs[b].r)<_0){
        if(a>b){int c=a;a=b;b=c;}
        as[ap++]=std::make_pair(a,b);
    }
}

int main(){

    int n=read();
    for(int i=0;i<n;i++){
        int x=read(),y=read(),r=read();
        cs[i].x=_c*x+_s*y;
        cs[i].y=-_s*x+_c*y;
        cs[i].r=r;
        es[i<<1]=(event){cs[i].x-cs[i].r,i,1};
        es[i<<1^1]=(event){cs[i].x+cs[i].r,i,0};
    }
    n<<=1;
    sort(es,es+n);
    for(int i=0;i<n;i++){
        event w=es[i];
        if(w.type){
            std::set<int,cmp>::iterator it=line.upper_bound(w.id);
            if(it!=line.end())chk(*it,w.id);
            if(it!=line.begin())--it,chk(*it,w.id);
            line.insert(w.id);
        }else{
            std::set<int,cmp>::iterator it=line.find(w.id);
            if(it!=line.begin()){
                int a=*--it;++it;++it;
                if(it!=line.end())chk(*it,a);
                --it;
            }
            line.erase(it);
        }
    }
    sort(as,as+ap);
    if(ap)
        ans=1;
    for(int i=1;i<ap;i++)if(as[i]!=as[i-1])++ans;
    printf("%d",ans);
    return 0;
}

原题（没用，应该没几个人做过吧，所以找不同就好了~