View Compilation Error

0_0_15126951_1738.cpp: In function 'int main()':
0_0_15126951_1738.cpp:30:32: error: 'a' was not declared in this scope
             scanf("%s%d%d%d%d",a[i].dir,&a[i].t,&a[i].v,&a[i].x,&a[i].y);
                                ^
0_0_15126951_1738.cpp:34:16: error: 'a' was not declared in this scope
             if(a[i].dir[0] == 'N') {
                ^
0_0_15126951_1738.cpp:39:34: error: 'y' was not declared in this scope
                         t[tt][k][y] = 1;
                                  ^
0_0_15126951_1738.cpp:49:34: error: 'y' was not declared in this scope
                         t[tt][k][y] = 1;
                                  ^
0_0_15126951_1738.cpp:58:31: error: 'y' was not declared in this scope
                     for(int k=y+a[i].v;k<=m;k+=a[i].v) {
                               ^
0_0_15126951_1738.cpp:68:31: error: 'y' was not declared in this scope
                     for(int k=y-a[i].v;k>=1;k-=a[i].v) {
                               ^