Compilare: main.cpp: In function 'int main()': main.cpp:38:49: warning: array subscript has type 'char' [-Wchar-subscripts] f[j][0]=f[j][1]=f[j][2]=f[j][3]=0,++f[j][ch[i+j]]; ^ main.cpp:43:19: warning: array subscript has type 'char' [-Wchar-subscripts] ++f[k][ch[j-l+k+1]],r+=cnt-maxim(f[k][0],f[k][1],f[k][2],f[k][3]); ^ main.cpp:16:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("perb.in","r",stdin); ^ main.cpp:17:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("perb.out","w",stdout); ^ main.cpp:19:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%s",&n,&m,ch+1); ^ main.cpp:46:44: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y),printf("%d\n",dp[x][y]); ^