find the maximum width & length of a box using for loops?

[bac3bac0mm]

There four sides of a wall(a square), the cost of building this wall:

1 side(length) $1200 per meter
2 side(width) $2500 per meter
1 side(length) $2500 per meter
the max of length & width are both 100

you have limited budget $20000 to best use to build the wall, the accuracy of length and width should be down to 0.1 meter, use two for loops to find out the best combination of length & width.

here is my code (wrong)

#include <stdio.h>

struct dimension {
  float length; /* river side length */
  float width;
};

void maxSize(float amount, struct dimension* dim) {

  /* Enter your code here */
  float i, j;
  float max_area = 0;
  if ((2500 * 300 + 1200 * 100 ) < amount) {
     dim->length = 100;
     dim->width = 100;
     return;
  }
  //length = i //width = j
  for (i=100; i>=0.1; i-=0.1)
    for (j=100; j>=0.1; j-=0.1)
      area = i*j;
      cost = i*1200 + (i+j*2) * 2500;
      if( cost < amount && area < max_area)
      break;
}

int main() {
  struct dimension dim;
  maxSize(20000, &dim);
}

[quzah]

You shouldn't break on whatever the first match is. You should instead store that, and compare your next loop pass to that. That way you can get whatever beats the current value, but still meets the requirement (over and over).

Quzah.