Compilare: user.cpp: In function ‘int main()’: user.cpp:90:9: warning: unused variable ‘m’ [-Wunused-variable] int m; ^ user.cpp: In function ‘char nextch()’: user.cpp:12:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, BUF_SIZE, 1, fi); ^ user.cpp: In function ‘int main()’: user.cpp:130:24: warning: iteration 3u invokes undefined behavior [-Waggressive-loop-optimizations] int p=x+l[i]; ^ user.cpp:129:9: note: containing loop for(int i=0;i<6;i++){ ^ user.cpp:125:22: warning: iteration 1u invokes undefined behavior [-Waggressive-loop-optimizations] l[2*i+1]=-len; ^ user.cpp:107:5: note: containing loop for(int i=0;i<3;i++){ ^