Compilare: main.cpp: In function 'int main()': main.cpp:16:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<s.size();i++) { ~^~~~~~~~~ main.cpp:35:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=2;i<s.size();i++) { ~^~~~~~~~~ main.cpp:10:9: warning: unused variable 'n' [-Wunused-variable] int n,m,a,b,c,vf=0,sol=0,n2,i,sm,l=1,lmax=0; ^ main.cpp:10:13: warning: unused variable 'a' [-Wunused-variable] int n,m,a,b,c,vf=0,sol=0,n2,i,sm,l=1,lmax=0; ^ main.cpp:10:15: warning: unused variable 'b' [-Wunused-variable] int n,m,a,b,c,vf=0,sol=0,n2,i,sm,l=1,lmax=0; ^ main.cpp:10:17: warning: unused variable 'c' [-Wunused-variable] int n,m,a,b,c,vf=0,sol=0,n2,i,sm,l=1,lmax=0; ^ main.cpp:10:30: warning: unused variable 'n2' [-Wunused-variable] int n,m,a,b,c,vf=0,sol=0,n2,i,sm,l=1,lmax=0; ^~ main.cpp:11:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("charlie.in","r",stdin); ^ main.cpp:12:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("charlie.out","w",stdout); ^ main.cpp:13:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &m); ^