描述

复数E包含实部x和虚部y, E=x+yi;E的模为:

输入n(<=1000)和n对(x,y);

按模数升序对复合体进行排序，如果模数相等，则按输入顺序排序。

排序后输出n行of (x_i,y_i,mod_i)，保留2个十进制小数。

输入

输入n和n对(x,y);

输出

输出排序后的n行(x,y,mod)。

样例输入

3
2 2
1 1
3 3

样例输出

1.00 1.00 1.41
2.00 2.00 2.83
3.00 3.00 4.24

code1（给struct取小名

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
typedef struct{
    double  x;
    double  y;
    double mo;
    int index;
}Complexnum;
int cmp(const void*a,const void *b){
     const Complexnum *num1=(const Complexnum*)a;
    const Complexnum *num2=(const Complexnum*)b;
    if(num1->mo>num2->mo) return 1;
    if(num1->mo<num2->mo) return -1;
    if(num1->index>num2->index) return 1;
    if(num1->index<num2->index) return -1;
    return 0;
}
int main(){
    int n;
    while(scanf("%d",&n)!=EOF){
        Complexnum *complexnum=(Complexnum *)malloc(n*sizeof(Complexnum));
        for(int i=0;i<n;i++){
            scanf("%lf%lf",&complexnum[i].x,&complexnum[i].y);
            double mo1=sqrt(complexnum[i].x*complexnum[i].x+complexnum[i].y*complexnum[i].y);
            complexnum[i].mo=mo1;
            complexnum[i].index=i;
        }
        qsort(complexnum,n,sizeof(Complexnum),cmp);
        for(int i=0;i<n;i++){
            printf("%.2lf %.2lf %.2lf\n",complexnum[i].x,complexnum[i].y,complexnum[i].mo);
        }
        free(complexnum);
    }
    return 0;
}

code2（不给struct取小名）

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
typedef struct{
    double  x;
    double  y;
    double mo;
    int index;
}Complexnum;
int cmp(const void*a,const void *b){
     const Complexnum *num1=(const Complexnum*)a;
    const Complexnum *num2=(const Complexnum*)b;
    if(num1->mo>num2->mo) return 1;
    if(num1->mo<num2->mo) return -1;
    if(num1->index>num2->index) return 1;
    if(num1->index<num2->index) return -1;
    return 0;
}
int main(){
    int n;
    while(scanf("%d",&n)!=EOF){
        Complexnum *complexnum=(Complexnum *)malloc(n*sizeof(Complexnum));
        for(int i=0;i<n;i++){
            scanf("%lf%lf",&complexnum[i].x,&complexnum[i].y);
            double mo1=sqrt(complexnum[i].x*complexnum[i].x+complexnum[i].y*complexnum[i].y);
            complexnum[i].mo=mo1;
            complexnum[i].index=i;
        }
        qsort(complexnum,n,sizeof(Complexnum),cmp);
        for(int i=0;i<n;i++){
            printf("%.2lf %.2lf %.2lf\n",complexnum[i].x,complexnum[i].y,complexnum[i].mo);
        }
        free(complexnum);
    }
    return 0;
}