clc
clear
printf("------------task_1----------\n")
c=[4.5 4.5 4.5 5.9 5.9 5.9 2.3 2.3 2.3 5.9 5.9 5.9]';
A=[1 0 1 1 0 1 0 0 0 0 0 0;
   0 0 0 0 0 0 1 0 1 1 0 1;
   0 1 0 0 1 0 0 0 0 0 0 0;
   0 0 0 0 0 0 0 1 0 0 1 0;
   1 0 0 0 0 0 1 0 0 0 0 0;
   0 0 0 1 0 0 0 0 0 1 0 0;
   0 1 0.7 0 0 0 0 1 0.7 0 0 0;
   0 0 0 0 1 0.7 0 0 0 0 1 0.7;
   1 1 0.7 0 0 0 1 1 0.7 0 0 0;
   0 0 0 1 1 0.7 0 0 0 1 1 0.7];
b=[3800 2700 4600 6000 3000 1100 3200 5500 6500 8200]';
[x_min,z_min,ec,extra]=glpk(c,A,b,zeros(12,1),[],"UUUULLLLSS","CCCCCCCCCCCC",1)

printf("------------task_2----------\n")
db=[5 5 -5 -5 0 0 0 0 0 0]';
i=1;
while(1)
  i=i+1;
  B=b+i*db;
  [x_min,z_min]=glpk(c,A,B,zeros(12,1),[],"UUUULLLLSS","CCCCCCCCCCCC",1);
  if((x_min(3)>=100) || (x_min(6)>=100) || (x_min(9)>=100) || (x_min(12)>=100))
    printf("%d %d %d %d Optimal solution\n",B(1),B(2),B(3),B(4))
    [x_min,z_min,ec,extra]=glpk(c,A,B,zeros(12,1),[],"UUUULLLLSS","CCCCCCCCCCCC",1)
    break
  else
    printf("%d %d %d %d No changes\n",B(1),B(2),B(3),B(4))
  endif
endwhile

printf("------------task_3----------\n")
b_task_3=[20000 20000 20000 20000 3000 1100 3200 5500 6500 8200]';
[x_min_task_3,z_min_task_3]=glpk(c,A,b_task_3,zeros(12,1),[],"UUUULLLLSS","CCCCCCCCCCCC",1)

dc=[0 0.1 0 0 0.1 0 0 0.1 0 0 0.1 0]';
j=1;
while(1)
  j=j+1;
  C=c+j*dc;
  [x_min_task_3,z_min_task_3]=glpk(C,A,b_task_3,zeros(12,1),[],"UUUULLLLSS","CCCCCCCCCCCC",1);
  if((x_min_task_3(3)>=100) || (x_min_task_3(6)>=100) || (x_min_task_3(9)>=100) || (x_min_task_3(12)>=100))
    printf("%d %d %d %d Optimal solution\n",C(2),C(5),C(8),C(11))
    [x_min_task_3,z_min_task_3]=glpk(C,A,b_task_3,zeros(12,1),[],"UUUULLLLSS","CCCCCCCCCCCC",1)
    break
  else
    printf("%d %d %d %d No changes\n",C(2),C(5),C(8),C(11))
  endif
endwhile