Write a C program to find the leading terminals.txt

#include<stdio.h>

char arr[18][3] ={{'E', '+', 'F'},{'E', '*', 'F'},{'E', '(', 'F'}, {'E', ')', 'F'},{'E', 'i', 'F'},{'E', '$', 'F'},
{'F', '+', 'F'},{'F', '*', 'F'},{'F', '(', 'F'},{'F', ')', 'F'},{'F', 'i', 'F'},{'F', '$', 'F'}, {'T', '+', 'F'},
{'T', '*', 'F'}, {'T', '(', 'F'},{'T', ')', 'F'},{'T', 'i', 'F'},{'T', '$', 'F'}};

char prod[] = "EETTFF";
char res[6][3] ={ {'E', '+', 'T'}, {'T', '\0'}, {'T', '*', 'F'},  {'F', '\0'}, {'(', 'E', ')'}, {'i', '\0'}};
char stack [5][2];
int top = -1;

void install(char pro, char re) {
    int i;
    for (i = 0; i < 18; ++i) {
        if (arr[i][0] == pro && arr[i][1] == re) {

            arr[i][2] = 'T';
            break;
        }
    }
    ++top;
    stack[top][0] = pro;
    stack[top][1] = re;
}

int main() {
    int i = 0, j;
    char pro, re, pri = ' ';

    for (i = 0; i < 6; ++i) {
        for (j = 0; j < 3 && res[i][j] != '\0'; ++j) {
            if (res[i][j] == '+' || res[i][j] == '*' || res[i][j] == '(' || res[i][j] == ')' || res[i][j] == 'i' || res[i][j] == '$') {
                install(prod[i], res[i][j]);
                break;
            }
        }
    }
    while (top >= 0) {
        pro = stack[top][0];
        re = stack[top][1];
        --top;
        for (i = 0; i < 6; ++i) {
            if (res[i][0] == pro && res[i][0] != prod[i]) {
                install(prod[i], re);
            }
        }
    }
    for (i = 0; i < 18; ++i) {
        printf("\n\t");
        for (j = 0; j < 3; ++j)
            printf("%c\t", arr[i][j]);
    }
    
    printf("\n\n");
    for (i = 0; i < 18; ++i) {
        if (pri != arr[i][0]) {
            pri = arr[i][0];
            printf("\n\t%c -> ", pri);
        }
        if (arr[i][2] == 'T')
            printf("%c ", arr[i][1]);
    }
    
}