如何使用scanf\fscanf读取一行并解析为变量？

#include<stdio.h>

int main() {
    int a, b;
    char op;

    printf("请输入一个算术表达式（如：2+3）：");
    scanf("%d%c%d", &a, &op, &b);

    printf("解析结果：a = %d, op = %c, b = %d\n", a, op, b);

    return 0;
}

#include<stdio.h>

int main() {
    int a, b;
    char op;

    FILE *file = fopen("input.txt", "r");
    if (file == NULL) {
        printf("无法打开文件\n");
        return 1;
    }

    fscanf(file, "%d%c%d", &a, &op, &b);

    printf("解析结果：a = %d, op = %c, b = %d\n", a, op, b);

    fclose(file);

    return 0;
}