Compilare: main.cpp: In function 'int main()': main.cpp:49:26: warning: left operand of comma operator has no effect [-Wunused-value] for(pos, j; j <= l ; ++j, ++pos){ ^ main.cpp:49:27: warning: right operand of comma operator has no effect [-Wunused-value] for(pos, j; j <= l ; ++j, ++pos){ ^ main.cpp:13:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("radio2.in", "r", stdin); ^ main.cpp:14:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("radio2.out", "w", stdout); ^ main.cpp:16:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d\n", &n, &m, &l, &k); ^ main.cpp:19:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s", s + 1); ^ main.cpp:33:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s", aux + 1); ^