Compilare: main.cpp: In function 'void SolveE2(std::__cxx11::string)': main.cpp:95:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (isdigit(s[it]) && it < s.size()) ~~~^~~~~~~~~~ main.cpp:115:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (!isdigit(s[it]) && it < s.size()) ~~~^~~~~~~~~~ main.cpp: In function 'void _cfun()': main.cpp:12:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ec.in", "r", stdin); ^ main.cpp:13:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ec.out", "w", stdout); ^ main.cpp: In function 'int main()': main.cpp:82:22: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized] return (c - b) / a;//*/ ^ main.cpp:56:9: note: 'a' was declared here int a, b, c, it = 0; ^ main.cpp:82:15: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized] return (c - b) / a;//*/ ~~~^~~~ main.cpp:56:12: note: 'b' was declared here int a, b, c, it = 0; ^ main.cpp:82:15: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized] return (c - b) / a;//*/ ~~~^~~~ main.cpp:56:15: note: 'c' was declared here int a, b, c, it = 0; ^ main.cpp:124:30: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized] double delta = b * b - 4 * a * c; ~~^~~ main.cpp:91:9: note: 'a' was declared here int a, b, c, d, it = 0; ^ main.cpp:124:22: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized] double delta = b * b - 4 * a * c; ~~^~~ main.cpp:91:12: note: 'b' was declared here int a, b, c, d, it = 0; ^ main.cpp:123:7: warning: 'd' may be used uninitialized in this function [-Wmaybe-uninitialized] c -= d; ~~^~~~ main.cpp:91:18: note: 'd' was declared here int a, b, c, d, it = 0;