Question

给出Clojure中的以下列表：

#include "math.h"
#include "malloc.h"
#include "stdlib.h"
#include "stdio.h"
#include "subroutines.h"

// Libreria para resolver sistemas lineales.

static double *sub_diag, * sup_diag, *diag, *d ;

// Function which allocates memory for the variables used inside the interpolation method
void inimem_spline(int n)
{
    int r = n-2, c = n-2; 
    int i, j;

    d=(double *) calloc(n,sizeof(double));
    if(d==NULL) {
        printf("\ninimem_spline:It is not possible to allocate memory\n");
        exit(19);
    }
    for(j=0;j<n;j++) d[j]=0.e+0;

    sub_diag=(double *) calloc(n-1,sizeof(double));
    if(sub_diag==NULL) {
        printf("\ninimem_spline:It is not possible to allocate memory\n");
        exit(20);
    }
    for(j=0;j<n;j++) sub_diag[j]=0.e+0;

    sup_diag=(double *) calloc(n-1,sizeof(double));
    if(sup_diag==NULL) {
        printf("\ninimem_spline:It is not possible to allocate memory\n");
        exit(21);
    }
    for(j=0;j<n;j++) sup_diag[j]=0.e+0;

    diag=(double *) calloc(n,sizeof(double));
    if(diag==NULL) {
        printf("\ninimem_spline:It is not possible to allocate memory\n");
        exit(22);
    }
    for(j=0;j<n;j++) diag[j]=0.e+0;

}

// Free Space of the Variables used inside the interpolation method.

void freemem_spline(int n)
{
    int i,j;

    for(j=0;j<n;j++) free(sub_diag[j]); 
    for(j=0;j<n;j++) free(sup_diag[j]); 
    for(j=0;j<n;j++) free(diag[j]); 
    for(j=0;j<n;j++) free(d[j]); 
    printf("\freemem_spline:Memmory free\n");

}

我想根据每对中的第二项按降序对它们进行排序。

即我希望它们分类为：

(def pairs '[(2,1),(3,2),(2,4)])

我的问题是：如何根据嵌套值对列表中的对进行排序？

Answer 1

使用sort-by：

(sort-by second > pairs)

如何根据嵌套值对列表中的对进行排序？

1 个答案: