Compilare: main.c: In function 'main': main.c:8:13: warning: implicit declaration of function 'gets' [-Wimplicit-function-declaration] for(gets(e),j=1,k=0;e[k];++k) ^~~~ main.c:6:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("matperm.in","r",stdin),freopen("matperm.out","w",stdout),scanf("%d\n",&n); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:6:37: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("matperm.in","r",stdin),freopen("matperm.out","w",stdout),scanf("%d\n",&n); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:6:71: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] freopen("matperm.in","r",stdin),freopen("matperm.out","w",stdout),scanf("%d\n",&n); ^~~~~~~~~~~~~~~~ ./ccCE3TsY.o: In function `main': main.c:(.text.startup+0x6d): warning: the `gets' function is dangerous and should not be used.