// Simplex optimization algorithm#include <stdlib.h>#include <stdio.h>void pivot(int N, int M, double **a, int p, int q) 
{  int j, k;  for (j = 0; j < N; j++)     for (k = M-1; k >= 1; k--)      if (j != p && k != q)        a[j][k] -= a[p][k] * a[j][q] / a[p][q];  for (j = 0; j < N; j++)    if (j != p)       a[j][q] = 0.0;  for (k = 1; k < M; k++)    if (k != q)      a[p][k] /= a[p][q];  a[p][q] = 1.0;}int simplex(int N, int M, double **a) 
{  int i, p, q;  do {    // find negative value in row 0    q = 0;    while (q < M && a[0][q] >= 0.0) q++;    //    p = 1;    while (p < N && a[p][q] <= 0.0) p++;    for (i = p + 1; i < N; i++)      if (a[i][q] > 0.0)        if (a[i][M - 1] / a[i][q] < a[p][M - 1] / a[p][q])          p = i;    if (q < M  && p < N )      pivot(N, M, a, p, q);  } while (q < M  && p < N );  return q == M;}int main(int argc, char *arvg[]) 
{  int i, j;#define N 6#define M 9double **a;  a = malloc(N * sizeof(double *));  for (i = 0; i < N; i++) 
  {    a[i] = malloc(M * sizeof(double));    for (j = 0; j < M; j++)      a[i][j] = 0.0;  }  a[0][0] = -1.0;  a[0][1] = -1.0;  a[0][2] = -1.0;   a[1][0] = -1.0;  a[1][1] = 1.0;  a[1][3] = 1.0;  a[1][8] = 5.0;  a[2][0] = 1.0;  a[2][1] = 4.0;  a[2][4] = 1.0;  a[2][8] = 45.0;  a[3][0] = 2.0;  a[3][1] = 1.0;  a[3][5] = 1.0;  a[3][8] = 27.0;  a[4][0] = 3.0;  a[4][1] = -4.0;  a[4][6] = 1.0;  a[4][8] = 24.0;  a[5][2] = 1.0;  a[5][7] = 1.0;  a[5][8] = 4.0;  if (simplex(N, M, a)) 
  {    printf("opt.: %f, %f %f %f\n", a[0][M-1], a[N-3][M-1], a[N-2][M-1], a[N-1][M-1]);  }  exit(0);}