Compilare: main.cpp: In function 'int main()': main.cpp:23:16: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] a[n + 1] = NULL; ^~~~ main.cpp:24:16: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] b[m + 1] = NULL; ^~~~ main.cpp:25:12: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] a[0] = NULL; ^~~~ main.cpp:26:12: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] b[0] = NULL; ^~~~ main.cpp:8:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.in", "r", stdin); ^ main.cpp:9:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.out", "w", stdout); ^ main.cpp:11:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &c); ^ main.cpp:15:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &c); ^ main.cpp:17:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &c); ^ main.cpp:21:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &c); ^