error: variable-sized object may not be initialized

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error: variable-sized object may not be initialized

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#1 by (1 votes)

1

The elements of chair points fulfill one of these conditions:

Within the row are minimal and within the column are maximum.

Inside the row they are maximum and inside the column they are minimum

 #include <stdio.h>
 #define N 10

typedef struct
{
    int fils, cols;  
    unsigned int mat[N][N];
}tmatriz;   


int main()
{
    tmatriz m1={4,3,{{4,4,1},{4,3,0},{3,5,0}, {4,2,0}}};

    int i, j;
    int maxFils [m1.fils] = {-999, -999, -999, -999};
    int minCols [m1.cols] = {999, 999, 999};    
    printf("Datos de la matriz m1:\n");
    for (i=0; i<m1.fils; i++)
    {
        for (j=0; j<m1.cols; j++)
            printf("%3u ", m1.mat[i][j]);
        printf("\n");
    }
    for (i=0; i<m1.fils; i++){
        for (j=0; j<m1.cols; j++){
            if (m1.mat [i] [j] > maxFils [i]){
                maxFils [i] = m1.mat [i] [j];
            }
            if (m1.mat [i] [j] < minCols [j]){
                minCols [j] = m1.mat [i] [j];
            }
        }
    }
    for (i=0; i<m1.fils; i++){
        for (j=0; j<m1.cols; j++){
            if (maxFils [i] == minCols [j]){
                printf ("Punto de silla en (%d, %d) y su valor es %d\n", i, j, m1.mat [i] [j]);
            }
        }
    }
}

I do not understand why this algorithm does not work for me

c matrices

asked by Jordi García 25.04.2017 в 15:08

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1 answer

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score 1 · Accepted Answer

I guess you're in C99, or that you use a compiler with variable length arrays support. The compiler tells you very clearly:

variable-sized object may not be initialized

You are using a array of variable length : the size of array is not known at compile time >, but in execution time .

At the moment of generating the code to initialize said array maxFils , the compiler does not know its size . So, does not know how many data to expect, nor how many bytes copy . The compiler does not know how to initialize it, precisely because it does not know its size.

You have 2 options:

Use fixed length arrays :

int maxFils[N] = { -999, -999, ... };

Initializes directly the elements of the array:

int maxFils[m1.fils];
int idx;

for( idx = 0; idx < m1.fils; ++idx )
  maxFils[idx] = -999;

The 1st option is the most portable among compilers.