编译错误，但是怎么也找不出来

#include <bits/stdc++.h>
using namespace std;
int n,i,j,x,y,s,t;
int f[10][8]={
    {6,0,1,2,4,5,6},{2,2,5},{5,0,2,3,4,6},{5,0,2,3,5,6},
    {4,1,2,3,5},{5,0,1,3,5,6},{6,0,1,3,4,5,6},{3,0,2,5},
    {7,0,1,2,3,4,5,6},{6,0,1,2,3,5,6}
};
int d[7][3][2]={
    {{0,0},{0,1},{0,2}},
    {{0,0},{1,0},{2,0}},
    {{0,2},{1,2},{2,2}},
    {{2,0},{2,1},{2,2}},
    {{2,0},{3,0},{4,0}},
    {{2,2},{3,2},{4,2}},
    {{4,0},{4,1},{4,2}}
};
char a[101],c[5][500];
signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    cin>>n>>a+1;
    for(i=1;i<=5;i++)
        for(j=1;j<=4*n-1;j++) c[i][j]='.';
    for(i=1;i<=n;i++){
        x=0;y=i*4;s=a[i]-'0';
        for(j=1;j<=f[s][0];j++){
            t=f[s][j];
            c[x+s[t][0][0]][y+d[t][0][1]]='X';
            c[x+s[t][1][0]][y+d[t][1][1]]='X';
            c[x+s[t][2][0]][y+d[t][2][1]]='X';
        }
    }
    for(i=1;i<=5;i++,cout<<"\n")
        for(j=1;j<=4*n-1;j++) cout<<c[i][j];
}

编译错误，

报错：

[Error] invalid types 'int[int]' for array subscript