map容器结构体离散化

小数坐标离散化：

#include"string.h"
#include"stdio.h"
#include"iostream"
#include"algorithm"
#include"queue"
#include"stack"
#include"stdlib.h"
#include"map"
#include"string"
#include"math.h"
#define inf 10000000
#define INF 0x3f3f3f3f
const double PI=acos(-1.0);
const double r2=sqrt(2.0);
const int M=100;
const int N=1010*502*2;
const double g=9.8;
#define eps 1e-10
using namespace std;
struct node
{
    double x,y;
    node(){}
    node(double xx,double yy)
    {
        x=xx;
        y=yy;
    }
    bool operator<(const node &b)const
    {
        if(fabs(x-b.x)<eps)
            return y<b.y;
        else
            return x<b.x;
    }
};
int main()
{
    int n,i;
    while(scanf("%d",&n)!=-1)
    {
        map<node,int>mp;
        int cnt=0;
        for(i=1;i<=n;i++)
        {
            node e;
            scanf("%lf%lf",&e.x,&e.y);
            if(!mp[e])
            mp[e]=++cnt;
        }
        double a,b;
        while(scanf("%lf%lf",&a,&b)!=-1)
        {
            node t(a,b);
            printf("%d
",mp[t]);
        }
    }
}

整数二维坐标离散化：

#include"string.h"
#include"stdio.h"
#include"iostream"
#include"algorithm"
#include"queue"
#include"stack"
#include"stdlib.h"
#include"map"
#include"string"
#include"math.h"
#define inf 10000000
#define INF 0x3f3f3f3f
const double PI=acos(-1.0);
const double r2=sqrt(2.0);
const int M=100;
const int N=1010*502*2;
const double g=9.8;
#define eps 1e-10
using namespace std;
struct node
{
    int x,y;
    node(){}
    node(int xx,int yy)
    {
        x=xx;
        y=yy;
    }
    bool operator<(const node &b)const
    {
        if(x==b.x)
            return y<b.y;
        else
            return x<b.x;
    }
};
int main()
{
    int n,i;
    while(scanf("%d",&n)!=-1)
    {
        map<node,int>mp;
        int cnt=0;
        for(i=1;i<=n;i++)
        {
            node e;
            scanf("%d%d",&e.x,&e.y);
            if(!mp[e])
            mp[e]=++cnt;
        }
        int a,b;
        while(scanf("%d%d",&a,&b)!=-1)
        {
            node t(a,b);
            printf("%d
",mp[t]);
        }
    }
}

同理三维多维也可以：

#include"string.h"
#include"stdio.h"
#include"iostream"
#include"algorithm"
#include"queue"
#include"stack"
#include"stdlib.h"
#include"map"
#include"string"
#include"math.h"
#define inf 10000000
#define INF 0x3f3f3f3f
const double PI=acos(-1.0);
const double r2=sqrt(2.0);
const int M=100;
const int N=1010*502*2;
const double g=9.8;
#define eps 1e-10
using namespace std;
struct node
{
    int x,y,z;
    node(){}
    node(int xx,int yy,int zz)
    {
        x=xx;
        y=yy;
        z=zz;
    }
    bool operator<(const node &b)const
    {
        if(z==b.z)
        {
            if(y==b.y)
                return x<b.x;
            else
                return y<b.y;
        }
        else
            return z<b.z;
    }
};
int main()
{
    int n,i;
    while(scanf("%d",&n)!=-1)
    {
        map<node,int>mp;
        int cnt=0;
        for(i=1;i<=n;i++)
        {
            node e;
            scanf("%d%d%d",&e.x,&e.y,&e.z);
            if(!mp[e])
            mp[e]=++cnt;
        }
        int a,b,c;
        while(scanf("%d%d%d",&a,&b,&c)!=-1)
        {
            node t(a,b,c);
            printf("%d
",mp[t]);
        }
    }
}