Compilare: main.cpp: In function 'int main()': main.cpp:16:18: warning: 'lastval' may be used uninitialized in this function [-Wmaybe-uninitialized] 16 | return (dsu[x] == x? x : father(dsu[x] = father(dsu[dsu[x]]))); | ~~~~~^ main.cpp:54:25: note: 'lastval' was declared here 54 | for(int lastcol = -1, lastval, i = 1; i <= n; i++, lastcol = -1) { | ^~~~~~~