无法在函数中将 int 指针数组转换为双指针数组

Question

我有一个函数应该将 int 指针数组转换为双指针数组。它看起来像这样：

double* intToDouble(int len , int*x){

    double* y;
    y =(double*)malloc(len*sizeof(double));
    for (int i=0; i<len ; i++){
        y[i]=(double)x[i];
    }
    return y;
}

但是，当尝试使用它时，我得到一个充满浮点 0 的数组。我也会把我的打印数组函数留在这里，以防它是相关的。

void printDoubleSignal(int len, double* x) {
    printf("%d: [", len);
    if (len > 0) {
        printf("%lf", x[0]);
        for (int i = 1; i < len; i++) printf(",%lf", x[i]);
    }
    printf("]\n");
}

这是我尝试从 int 转换为浮点数组 10 后得到的结果：[1,2,3,4,5,0,0,0,0,0]

10: [0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000]

编辑 根据要求，以下是其余代码：

#include <stdio.h>
#include <stdlib.h>
#include <complex.h>
#include <math.h>

int* readSignal(int* len) {
    int* x;
    char c;
    scanf("%d:", len);
    x = calloc(*len, sizeof(int));
    do c = getchar(); while (c != '[');
    if (*len > 0) {
        scanf("%d", &x[0]);
        for (int i = 1; i < *len; i++) scanf(",%d", &x[i]);
    }
    do c = getchar(); while (c != ']');
    return x;
}

void printSignal(int len, int* x) {
    printf("%d: [", len);
    if (len > 0) {
        printf("%d", x[0]);
        for (int i = 1; i < len; i++) printf(",%d", x[i]);
    }
    printf("]\n");
}

void printDoubleSignal(int len, double* x) {
    printf("%d: [", len);
    if (len > 0) {
        printf("%lf", x[0]);
        for (int i = 1; i < len; i++) printf(",%lf", x[i]);
    }
    printf("]\n");
}

int* zeroPad(int len, int* x, int n){

    int i;
    x = (int*)realloc(x, sizeof(int) * n);
    for (i=len; i<n ; i++){
        x[i]=0;
    }
    return x;
}

double* intToDouble(int len , int* x){

    double *y;
    y =(double*)malloc(len*sizeof(double));
    for (int i=0; i<len ; i++){
        printf("x[%d]=%lf\n",i, x[i]);
        y[i]=x[i];
        printf("y[%d]=%lf\n",i, y[i]);
    }
    return y;
}

int main()
{
    int *x , len=5;
    double *y;
    x = readSignal(&len);
    printSignal(len,x);
    x = zeroPad(&len,x,10);
    printSignal(len,x);
    y = intToDouble(len,x);
    printDoubleSignal(len ,y);

    return 0;
}

编辑 2 这是输入/输出的确切文本（第一行是输入，其余是输出）：

5:[1,2,3,4,5]
5: [1,2,3,4,5]
10: [1,2,3,4,5,0,0,0,0,0]
x[0]=-0.000000
y[0]=-0.000000
x[1]=-0.000000
y[1]=-0.000000
x[2]=-0.000000
y[2]=-0.000000
x[3]=-0.000000
y[3]=-0.000000
x[4]=-0.000000
y[4]=-0.000000
x[5]=-0.000000
y[5]=-0.000000
x[6]=-0.000000
y[6]=-0.000000
x[7]=-0.000000
y[7]=-0.000000
x[8]=-0.000000
y[8]=-0.000000
x[9]=-0.000000
y[9]=-0.000000
10: [0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000]

Answer 1

您忘记接收zeroPad 的结果。该函数使用realloc()，因此传递的指针可能无效。该函数返回新指针，因此您必须将其分配给x。

这表示main()函数中的那一行

    zeroPad(5,x,10);

应该是

    x = zeroPad(5,x,10);