foo.cc: In function 'int main()':
foo.cc:20:1: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
 if(a[i]==a[j]);
 ^~
foo.cc:21:1: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
 {
 ^
foo.cc:6:7: warning: unused variable 'j' [-Wunused-variable]
 int i,j,k,len,t,a[10];
       ^
foo.cc:6:9: warning: unused variable 'k' [-Wunused-variable]
 int i,j,k,len,t,a[10];
         ^

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