Compilare: user.cpp: In function ‘int main()’: user.cpp:14:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i <= n; i++) ^ user.cpp:15:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 1; j <= n; j++) { ^ user.cpp:19:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int u = 1; u <= n; u++) { ^ user.cpp:20:76: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (s[i][j] - s[i-u][j] - s[i][j-u] + s[i-u][j-u] == u*u) spartial[u]++; ^ user.cpp:23:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i <= n; i++) ^