//uva12385 #include<iostream> #include<cstdio> #define max(a,b) ((a)>(b)?(a):(b)) main(){ int t, n, i; int s[100010]; int last[100010]; scanf("%d",&n); while (n--){ scanf("%d",&t); for (i = 0; i < t; i++){ scanf("%d",&s[i]); last[s[i]] = 0; } int ans[100010] = {0}; last[s[0]] = 1; ans[0] = 0; for (i = 1; i < t; i++){ if (last[s[i]] != 0){ ans[i] = max(ans[i - 1], ans[last[s[i]]] + 1); } else ans[i] = ans[i-1]; last[s[i]] = i; } printf("%d\n", ans[t-1]); } }