C语言编程，如何根据一个值，查找一个对应关系表，获得对应值呢？

Question

C语言编程，如何根据一个小范围值区间，查找一个对应关系表，获得一个对应值呢
例如电压值为2000~2026(mv),
其对应功率值为-52(dB),如何用C语言编程，完成建表，查表，获得结果呢？

Answer 1

/*17点：一一对应版本*/
#include <stdio.h>

#define NG (0xFF)

//data structure
typedef struct
{
        int voltage;
        int power;  
}stVoltPowerTbl;

//table
const stVoltPowerTbl myTable[] = 
{
        {-19,1083},
        {-18,1049},
        {-17,1025},
        {-16,996},
        //add your data 
};

int Find(int voltage)
{
        int Ret = NG;
        int i = 0;

        for(i=0;i<((sizeof(myTable))/(sizeof(stVoltPowerTbl)));i++)
        {
                if(myTable[i].voltage == voltage)
                {
                        Ret = myTable[i].power;
                }
        }
        return Ret;
}

int main()
{
        int Ret = 0;

        Ret = Find(-17);

        if(Ret != NG)
        {    
                printf("power = %d \n",Ret);
        }
        else
        {    
                printf("Error Voltage! \n");
        }

        return 0;
}

/*21点：根据范围求对应值版本*/
#include <stdio.h>

#define NG (0xFF)

//data structure
typedef struct
{
        int power;      
        int minVoltage;
        int maxVoltage;
}stVoltPowerTbl;

//table
const stVoltPowerTbl myTable[] = 
{
        {-55,2080,2094},
        {-54,2060,2075},
        {-52,2000,2026},
        //add your data 
};


int Find(int voltage)
{
        int Ret = NG;
        int i = 0;

        for(i=0;i<((sizeof(myTable))/(sizeof(stVoltPowerTbl)));i++)
        {
                if((myTable[i].minVoltage < voltage)&&(myTable[i].maxVoltage > voltage))
                {
                        Ret = myTable[i].power;
                }
        }
        return Ret;
}

int main()
{
        int Ret = 0;

        Ret = Find(2001);

        if(Ret != NG)
        {    
                printf("power = %d \n",Ret);
        }
        else
        {    
                printf("Error Voltage! \n");
        }

        return 0;
}