Question

我正在尝试通过将从文件读取的值插入到C ++映射中来消除存储在文件中的重复项。输入：

1 1 2 3

以下是逻辑：

do
{
    ret = read(fd, (void*)&value, 1);
    if(ret != -1 && ret != 0 && value != 10 && value != 32 )
    {
            insertVal = value - 48;
            cout<<"value computed " << insertVal << endl;
            if(numArr[insertVal] == 0)
                numArr[insertVal] = 100;
    }
    insertVal = 0;

}while(ret!= 0);

输出：

value computed 1
value computed 1
value computed 2
value computed 3

如果我使用map，则使用数组

逻辑更改为

do
{
    ret = read(fd, (void*)&value, 1);
    if(ret != -1 && ret != 0 && value != 10 && value != 32 )
    {
            insertVal = value - 48;
            cout<<"value computed " << insertVal << endl;
            numberMap.insert(std::pair<int, int>(insertVal, 100));
    }
    insertVal = 0;

}while(ret!= 0);

输出：

value computed 4200410 value computed 4200449 value computed 4200432 value computed 4200449 value computed 4200410 value computed 4200450 value computed 4200432 value computed 4200451 value computed 4200410

我的问题是，为什么地图插入对垃圾有价值。请帮帮我。

Answer 1

你过度复杂化了。读入std::map的简单方法是

std::map<int, int> numberMap;
std::ifstream fd("file_name");
...
for (int value; fd >> value;) {
    if (value == 10 || value == 32) continue;
    int insertVal = value - 48;
    numberMap[insertVal] = 100;
}

垃圾值被插入到地图中

1 个答案: