http://en.wikipedia.org/wiki/Simplex_algorithm

SimplexAlgorithm.c

// http://en.wikipedia.org/wiki/Simplex_algorithm 
#include "SimplexAlgorithm.h"
#define M 200
#define N 100

int main(void)
{
    int n, m, i, j;
    printf("请输入总的变量的个数和松弛变量的个数：\n");
    scanf("%d %d", &m, &n);

    typedef struct 
    {
        float a[M][N];
        float b[M];
        float c[N];
        float d[N];
    }vector;

    vector sample;

    printf("请输入所有变量的价值系数：\n");
    for (i = 0; i < n; ++i)
    {
        scanf("%f", &sample.c[i]);
    }

    for (i = 0; i < n; ++i)
    {
        //初始化检验数组d=c
        sample.d[i] = sample.c[i]
    }

    printf("输入约束方程组右端的系数\n");
    for (i = 0; i < m; ++i)
    {
        scanf("%f", &sample.b[i]);
    }

    printf("输入典式中约束方程组的系数矩阵：\n");
    for (i = 0; i < m; ++i)
    {
        for (j = 0; j < n; ++j)
        {
            scanf("%f", &sample.a[i][j]);
        }
    }

    while(0 == determine(sample.d, n))
    {
        i = findMaxIndex(sample.d, n);
        j = findBasicVariable(sample.b, sample.a, i)
    }
    return 0;
}

SimplexAlgorithm.h

// http://en.wikipedia.org/wiki/Simplex_algorithm 
#include <stdio.h>
#include <math.h>

int determine(float *d, int n)
{
    //判断一个数组是否所有的元素都小于等于零
    //如果是，返回1，否则返回0
    int flag = 1;
    int i;

    for (i = 0; i < n; ++i)
    {
        if (d[i] > 0)
        {
            flag = 0;
            break;
        }
    }

    return flag;
}

int findMaxIndex(float *d, int n)
{
    //返回一个数组的最大值的下标
    float max;
    int i, maxIndex;

    max = d[0];
    maxIndex = 0;
    for (i = 1; i < n; ++i)
    {
        if (d[i] > max)
        {
            max = d[i];
            maxIndex = i;
        } 
    }

    return maxIndex;
}

int findBasicVariable(float *b, float (*a)[N], int i)
{
    //返回需要变成基变量竖直方向的下标
    float temp[M];
    int j, k, basicVariableIndex;
    for (j = 0, k = 0; j < m; ++j, ++k)
    {
        if (a[i][j] = 0)
        {
            temp[k] = 0;
        }
        else
        {
            temp[k] = (float)(b[j] / a[i][j]);
        }
    }

    basicVariableIndex = findMaxIndex(temp, k);
    return basicVariableIndex;
}