N7OAPs - Online C Compiler & Debugging Tool

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

int main(){
    int i,j,k=1;
    int a,b;
    int **mat;
    scanf("%d %d",&a,&b);

    mat = (int**)malloc(sizeof(int*)*a);
 	if(mat == NULL){ printf("ERROR\n");
 	return 0;
 	}
	for (i = 0; i < a; i++) {
		mat[i] = (int*)malloc(sizeof(int)*b);
 		if(mat[i] == NULL){ printf("ERROR\n");
 		return 0;
 		}
 		}

	for (i = 0; i < a; i++) {
		for (j = 0; j < b; j++) {
			mat[i][j] = k++;
		}
	}
    for(i=0;i<a;i++){
        for(j=0;j<b;j++){
            printf("%d ",mat[i][j]);
        }
        printf("\n");
    }
	for(i=0;i<a;i++){
		free(mat[i]);
	}

    free(mat);

    return 0;
}