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Index › Program to find the shortest path
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 Program to find the shortest path (Read 2620 times)
 Ryan.pennell Program to find the shortest path Jun 17th, 2010, 9:30pm   Hello, I'm new to processing, but have been using arduino for awhile now, but I can't understand what is wrong with this program.the program is supposed to take a goal position, store it as 0, and take each position around it one number higher. like...2123456101234521234563234567it stores obsticles as -2 and the unmapped areas as -1heres the part of the code that has the problem.void plot() {  for (int i = 0; i < col; i++) {    for (int j = 0; j < row; j++) {      ways[i][j] = -1;    }  }  refresh();  ways[gx] [gy] = 0;  for (int z = 0; ways[ox] [oy] == -1; z++) {    for (int i = 0; i < col; i++) {      for (int j = 0; j < row; j++) {        if (ways[i] [j] == z) {          if (ways[i-1] [j] == -1) {            ways[i-1] [j] = z+1;          }          if (ways[i+1] [j] == -1) {            ways[i+1] [j] = z+1;          }          if (ways[i] [j-1] == -1) {            ways[i] [j-1] = z+1;          }          if (ways[i] [j+1] == -1) {            ways[i] [j+1] = z+1;          }        }      }    }  }}and the error...Exception in thread "Animation Thread" java.lang.ArrayIndexOutOfBoundsException: 20      at plotter.plot(plotter.java:61)      at plotter.mouseReleased(plotter.java:44)      at processing.core.PApplet.handleMouseEvent(PApplet.java:1611)      at processing.core.PApplet.dequeueMouseEvents(PApplet.java:1544)      at processing.core.PApplet.handleDraw(PApplet.java:1436)      at processing.core.PApplet.run(PApplet.java:1327)      at java.lang.Thread.run(Thread.java:619)
 PhiLho Re: Program to find the shortest path Reply #1 - Jun 17th, 2010, 10:50pm   Hard to tell from your snippet (we don't have array sizes, where ox/oy come, etc.) but I guess the (classical) error comes from ways[i+1] [j] for example (and might fail on ways[i-1] [j] too).Beware of bounds!
 Ryan.pennell Re: Program to find the shortest path Reply #2 - Jun 18th, 2010, 12:50pm   ox and oy is the x and y cordinates of the object that needs to move to the goal.  gx and gy is the x and y position of the goal.  thanks for the out of bounds comment.  I'll try that.
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