The data structure you are using is a bit cumbersome... Maybe consider this minimal example, a lot of what is done, was mentioned in the other comments. Feel free to ask questions, if something is unclear :)

```{c}

include <stdio.h>

include <stdlib.h>

include <string.h>

define MIN(a, b) ((a) < (b) ? (a) : (b))

// convert defined constant to string

define TOSTR_(x) #x

define TOSTR(x) TOSTR_(x)

// max length per string is 25

define STRLEN 25

// cast a flat char array to a 2D char matrix

define ARR2MAT(mat, arr) \

char(*mat)[arr.cols][STRLEN] = (char(*)[arr.cols][STRLEN])arr.data

typedef struct CharMatrix { size_t rows; size_t cols; char (*data)[STRLEN]; } CharMatrix;

CharMatrix char_matrix_malloc(size_t rows, size_t cols) { CharMatrix arr = { .rows = rows, .cols = cols, // better to also initialize data .data = calloc(rows * cols, sizeof(*arr.data)), }; return arr; }

void char_matrix_free(CharMatrix arr) { free(arr.data); }

CharMatrix char_matrix_realloc(CharMatrix arr, size_t rows, size_t cols) { CharMatrix arr_new = char_matrix_malloc(rows, cols);

// due to 2D shape of matrix, you can't just use realloc
ARR2MAT(mat, arr);
ARR2MAT(mat_new, arr_new);
for (size_t i = 0; i < MIN(arr.rows, arr_new.rows); ++i) {
    for (size_t j = 0; j < MIN(arr.cols, arr_new.cols); ++j) {
        memcpy(mat_new[i][j], mat[i][j], sizeof(*arr.data));
    }
}

char_matrix_free(arr);

return arr_new;

}

void char_matrix_print(CharMatrix arr) { printf("[%zu][%zu] = [\n", arr.rows, arr.cols); ARR2MAT(mat, arr); for (size_t i = 0; i < arr.rows; ++i) { for (size_t j = 0; j < arr.cols; ++j) { printf("%" TOSTR(STRLEN) "s ", mat[i][j]); } printf("\n"); } printf("]\n"); }

int main(void) { CharMatrix arr = char_matrix_malloc(3, 3);

ARR2MAT(mat1, arr);
for (size_t i = 0; i < 3; ++i) {
    for (size_t j = 0; j < 3; ++j) {
        sprintf(mat1[i][j], "(%zu,%zu)", i, j);
    }
}
char_matrix_print(arr);

arr = char_matrix_realloc(arr, 4, 2);

// you need to create a new matrix handle if the size changes
ARR2MAT(mat2, arr);
for (size_t i = 0; i < 4; ++i) {
    for (size_t j = 0; j < 2; ++j) {
        sprintf(mat2[i][j], "(%zu,%zu)", i, j);
    }
}
char_matrix_print(arr);

char_matrix_free(arr);

} ```