Compilare: main.cpp: In function 'int main()': main.cpp:5:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("trompeta.in","r",stdin); ^ main.cpp:6:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("trompeta.out","w",stdout); ^ main.cpp:7:44: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] char c;int n,m,k;scanf("%d %d\n",&n,&m); ^ main.cpp:8:43: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for(int i=1; i<=n; i++){scanf("%c",&c); ^ main.cpp:9:30: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized] while(k&&(s[k]<c)&&(k+n-i>=m))--k; ~^~