View Compilation Error

0_0_32683801_28792.cpp: In function 'int main()':
0_0_32683801_28792.cpp:8:9: error: 'cas' was not declared in this scope
     for(cas=1;cas<=t;cas++){
         ^
0_0_32683801_28792.cpp:11:42: error: 'a' was not declared in this scope
         for(int i=1;i<=n;i++)scanf("%d",&a[i]);
                                          ^
0_0_32683801_28792.cpp:14:16: error: 'a' was not declared in this scope
             if(a[j]>n-j)flag=0;
                ^
0_0_32683801_28792.cpp:15:16: error: 'a' was not declared in this scope
             if(a[j]-a[j+1]==1&&a[j+1]!=0){
                ^
0_0_32683801_28792.cpp:18:16: error: 'a' was not declared in this scope
             if(a[j]==0)cnt++;
                ^