Compilare: user.cpp: In function ‘void createKmpTable(std::string, short unsigned int*)’: user.cpp:20:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < a.length(); ++i) { ^ user.cpp: In function ‘void read()’: user.cpp:62:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < N; i++) { ^ user.cpp: In function ‘void write()’: user.cpp:70:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < N; ++i) { ^ user.cpp: In function ‘bool finished()’: user.cpp:91:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < N; ++i) { ^ user.cpp: In function ‘void solve()’: user.cpp:109:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < N; ++i) {if(used[i] == 1) continue; ^ user.cpp:110:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < N; ++j) { ^ user.cpp:118:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < N; ++j) {if(i == j || used[j]) continue; ^ user.cpp:105:15: warning: unused variable ‘x’ [-Wunused-variable] int j, k, x, ^ user.cpp: In function ‘int main()’: user.cpp:140:9: warning: unused variable ‘i’ [-Wunused-variable] int i; ^ user.cpp: In function ‘void solve()’: user.cpp:122:41: warning: ‘l’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(index == -1 || k > l) { ^