#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdio_ext.h>

int **m_realloc(int **m, size_t rows, size_t columns){

    m=realloc(m, rows*sizeof(int*));

    for(size_t y=0; y<rows; y++){

        m[y]=realloc(m[y], columns*sizeof(int));
    }

    return m;
}

void m_fill(int **m, size_t rows, size_t columns, size_t or, size_t oc, int max){

    srand((unsigned)time(NULL));

    size_t aux_y=0, aux_x=0;

    if(rows!=or && columns!=oc){

        aux_y=or;
        aux_x=0;

        for(size_t y=aux_y; y<rows; y++){

            for(size_t x=aux_x; x<columns; x++){

                m[y][x]=rand()%max;
            }
        }

        aux_y=0;
        aux_x=oc;

        for(size_t y=aux_y; y<(rows-1); y++){

            for(size_t x=aux_x; x<columns; x++){

                m[y][x]=rand()%max;
            }
        }

    }else{

        if(rows!=or){

            aux_y=or;
            aux_x=0;

        }else{

            aux_y=0;
            aux_x=oc;
        }

        for(size_t y=aux_y; y<rows; y++){

            for(size_t x=aux_x; x<columns; x++){

                m[y][x]=rand()%max;
            }
        }
    }
}

void m_show(int **m, size_t rows, size_t columns){

    printf("n");

    for(size_t y=0; y<rows; y++){

        for(size_t x=0; x<columns; x++){

            printf("[%d]t", m[y][x]);
        }

        printf("n");
    }

    printf("n");
}

void m_free(int **m, size_t rows){

    for(size_t i=0; i<rows; i++){

        free(m[i]);
    }

    free(m);
}

int main(void){

    int max=0;

    size_t or=0, oc=0;
    ssize_t rows=0, columns=0;

    bool decreased=false;

    unsigned char choice='';

    int **m=NULL;

    do{

        do{

            printf("nLinhas >");
            scanf("%ld", &rows);

            printf("Colunas >");
            scanf("%ld", &columns);

            if(rows<=0 || columns<=0){

                printf("n* Número de linhas ou colunas inválidos!n");

            }else{

                if(rows<or){

                    decreased=true;

                }else if(columns<oc){

                    decreased=true;

                }else if(rows==or && columns==oc){

                    decreased=true;

                }else{

                    decreased=false;
                }
            }

        }while(rows<=0 || columns<=0);

        if(decreased==false){

            if(or!=0 && oc!=0){

                printf("nValor máximo dentro de cada um dos novos campos >");
                scanf("%d", &max);

            }else{

                printf("nValor máximo dentro de cada campo >");
                scanf("%d", &max);
            }
        }

        m=m_realloc(m, rows, columns);

        if(decreased==false){

            m_fill(m, rows, columns, or, oc, max);
        }

        m_show(m, rows, columns);

        __fpurge(stdin);

        or=rows;
        oc=columns;

        printf("Deseja redimensionar a matriz [Y/n]?");
        choice=getchar();

    }while(choice=='y' || choice=='Y');

    printf("n");

    m_free(m, rows);

    m=NULL;

    return 0;
}