未声明错误结构（此函数首次使用）

Question

我在代码中使用了结构。看起来一切正常，我不太确定为什么会产生此错误。我觉得我已经明确声明了struct运算符。仍然出现以下错误：

operators undeclared (first use in this function)

这是我的代码：

    #include<stdio.h>
    #include <stdlib.h>
    #include "input.h"
    #include "operations.h"

    typedef int (*arithmeticFcn)(int, int);


    struct operators
    {
        char symbol;
        char opName[10];
        arithmeticFcn fcn;
    };

    int main() 
    {
        int opNum, res;

        struct operators calc[4] = 
        {
            {'+', "Add", addition},
            {'-', "Subtract", subtract},
            {'*', "Multiply", multiply},
            {'/', "Divide", divide}
        };

        for(int i=0; i<4; i++) 
        {
            int j= rand() % 4;
            struct operators temp = calc[i];
            operators[i] = calc[j];
            calc[j] = temp;
            printf("%d or %s: %s", i, operators.symbol, operators.opName);
        }

        printf("Enter Hotkey: ");
        scanf("%i || &c", &opNum, &operators.symbol);
        res = (operators[opNum || operators.symbol]) (op1, op2);

        printf("%i %c %i = %i", op1, operators.symbol, op2, res);

        return 0;
    }