Malloc.h not found - C (СИ)

#include <stdio.h>
#include <malloc.h>
 
#define myt int
 
// jghtltkbyt nbgjd
typedef struct Line { // jlyjvthysq vfccbd
    int SIZE; // hfpvthb
    int *l;
};
typedef struct Matrix{
    int lines;
    Line *a;
};
 
// prototypes of func
void GetMatrix(Matrix *); // sozdanie matrizu
void OutMatrix(Matrix);
int Nolvch(int *);
int Summ(Matrix *);
void Vector(Matrix *,Line *);
 
int main()
{
    Matrix matr = { 0, NULL };
    Line b = { 0, NULL };
    int c;
    do{
        Matrix m;
        GetMatrix(&m);
        OutMatrix(m);
        Vector(&matr, &b);
        
        scanf_s("%d", &c);
    } while (c != 0);
    return 0;
}
 
void GetMatrix(Matrix * x)
{
    printf("vvedi kolvo strock: ");
    scanf_s("%d", &x->lines, sizeof(int));
    x->a = (Line *)malloc(x->lines * sizeof(Line));
    
    for (int i = 0; i < x->lines; ++i)
    {
        printf("Sizeof(m[%i]) = ", i);
        scanf_s("%i", &x->a[i].SIZE, sizeof(x->a[i].SIZE));
        x->a[i].l = (int *)malloc(x->a[i].SIZE*sizeof(int));
        
        for (int j = 0; j < x->a[i].SIZE; j++)
        {
            printf("\tm[%d,%d] = ", i,j);
            scanf_s("%i", &x->a[i].l[j], sizeof(int));
        }
    }
}
 
int Nolvch(int a)
{
    int i = 0;
    int n = 0;
    while (a > 0)
    {
        n = a % 10;
        if (n = 0)
        {
            return 1;
        }
        a = a / 10;
    }
    
    return 0;
}
 
int Summ(Line *a)
{
    int *summ;
    
    for (int j = 0; j <a->SIZE; j++)
    {
        
        if (Nolvch(a->l[j]) == 0)
            *summ += a->l[j];
    }
    return *summ;
    
}
 
void vector(Matrix *matr, Line *b)
{
    int i, j, n, m, c, flag, s;
    Line PLINE;
    int *pElem;
    n = matr->lines;
    PLINE= matr->lines;
    n = matr->n;
    b->m = n;
    b->line = (int *)calloc(n, sizeof(int));
    for (i = 0; i < n; i++){
        s = 0;
        m = pLine->m;
        pElem = pLine->line;
        for (j = 0; j < m; j++){
            c = *pElem;
            flag = 1;
            while ((c > 0) && (flag == 1)){
                if (c % 10 == 0) flag = 0;
                c /= 10;
            };
            if (flag) s += *pElem;
            pElem++;
        }
        b->line[i] = s;
        pLine++;
    }
    output_v(b);
}

void OutMatrix(Matrix x)
{
    printf("matriza : \n");
    for (int i = 0; i < x.lines; i++) 
    {
        for (int j = 0; j < x.a[i].SIZE; j++)
        {
            printf("%i%s", x.a[i].l[j]," ");
        }
        printf("\n");
    }
}