C/C++ 控制浮点型精度

先乘取整再除

float fScore;
fScore=0.123456;
//*100表示保留的精度为0.01
//+0.005是为了四舍五入
int u32Score = (fScore+0.005) * 100;
fScore = (float)u32Score / 100;

字符串法

/** 计算浮点型四舍五入。*/
float BaseConstruction::getAccuracy(float input,unsigned int accuracy)
{
#define buf_size 100
    //通过输入生成精度字符串 （%0.*f）
    char accuracyBuf[buf_size];
    sprintf_s(accuracyBuf,buf_size,"%%0.%df",accuracy);

    //通过输入生成对应精度的float形打印输出
    char outputBuf[buf_size];
    sprintf_s(outputBuf,buf_size,accuracyBuf,input);

    //回转回float行数据
    float output = atof(outputBuf);
    return output;
}

参考：

1.https://www.cnblogs.com/Again/p/6406848.html