View Compilation Error

1_1030_3545_17807.cpp: In function 'int main()':
1_1030_3545_17807.cpp:29:4: error: 's1' was not declared in this scope
    s1=0;
    ^
1_1030_3545_17807.cpp:30:4: error: 't1' was not declared in this scope
    t1=0;
    ^
1_1030_3545_17807.cpp:41:20: error: 'q1' was not declared in this scope
     while(s1<t1&&a[q1[t1-1]]<=a[i]) t1--;
                    ^
1_1030_3545_17807.cpp:42:5: error: 'q1' was not declared in this scope
     q1[t1++]=i;
     ^