Compilare: main.cpp: In function 'void df(int)': main.cpp:64:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<v[nod].size(); i++) ~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:103:39: warning: unused variable 'j' [-Wunused-variable] int i, y, sol, z, x, x1, x2, y1, y2, j; ^ main.cpp:100:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pirati.in","r",stdin); ^ main.cpp:101:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pirati.out","w",stdout); ^ main.cpp:102:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d\n",&n, &m, &p); ^ main.cpp:105:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n",s[i]); ^ main.cpp:126:42: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d",&x1, &y1, &x2, &y2); ^ main.cpp: In function 'int lca(int, int)': main.cpp:95:9: warning: 'r' may be used uninitialized in this function [-Wmaybe-uninitialized] return r; ^ main.cpp: In function 'int main()': main.cpp:131:32: warning: 'r' may be used uninitialized in this function [-Wmaybe-uninitialized] sol=ss[x]+ss[y]-ss[z]-ss[tt[z]]; ~~~~^