Compilare: main.c:3:6: warning: return type of 'main' is not 'int' [-Wmain] void main () { ^~~~ main.c: In function 'main': main.c:12:5: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf (f_in, "%d%d", &n, &m); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:20:13: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf (f_in, "%d", &tabla[i][j]); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:42:13: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf (f_in, "%d", &tabla[i][j]); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:62:27: warning: 'xj' may be used uninitialized in this function [-Wmaybe-uninitialized] if (i==xi || j==xj) { ~^~~~ main.c:51:20: warning: 'min_j' may be used uninitialized in this function [-Wmaybe-uninitialized] if (mj<=min_j) { ^ main.c:5:31: warning: 'xi' may be used uninitialized in this function [-Wmaybe-uninitialized] int i,j,mi,mj,min_i,min_j,xi,xj; ^~ main.c:29:20: warning: 'min_i' may be used uninitialized in this function [-Wmaybe-uninitialized] if (mi<=min_i) { ^