Compilare: user.cpp: In function ‘int main()’: user.cpp:23:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i<= n; ++i) scanf("%d", &v[i]); ^ user.cpp:24:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i<= n; ++i) ^ user.cpp:26:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = i+1; j<= n; ++j) ^ user.cpp:35:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i<= n; ++i) ^ user.cpp:37:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = i+1; j<= n; ++j) ^ user.cpp:43:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(dsp[poz][k].val == sum - v[i] - v[j]) ^ user.cpp:20:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("oite.in", "r", stdin); ^ user.cpp:21:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("oite.out", "w", stdout); ^ user.cpp:22:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &sum); ^ user.cpp:23:50: 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("%d", &v[i]); ^