Compilare: main.cpp: In function 'int main()': main.cpp:22:27: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare] 22 | for (int i = 0; i < strlen(s); ++i) | ~~^~~~~~~~~~~ main.cpp:53:27: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare] 53 | for (int i = 0; i < strlen(s); ++i) | ~~^~~~~~~~~~~ main.cpp:52:19: warning: unused variable 'sum' [-Wunused-variable] 52 | int k(0), sum(0); | ^~~ main.cpp:132:25: warning: unused variable 'x4' [-Wunused-variable] 132 | int x1, x2, x3, x4, c(0); | ^~