View Compilation Error

0_0_17648687_20880.cpp: In function 'int rec(int)':
0_0_17648687_20880.cpp:37:9: error: redeclaration of 'int t'
     int t = unique(used,used + t) - used;
         ^
0_0_17648687_20880.cpp:27:15: note: 'int t' previously declared here
     int s = 0,t = 0,used[MAX_C];
               ^