This is my first question here.

My latest assignment is to create a random walk program using a 2-d array. The program worked fine until I tried to put this code into a function:

```
for(int i = 0; i < 100; i++){
//reset field of flowers for each attempt
populateAry(ary);
int row = 6, col = 1; //reset position
int position = ary[row][col]; //start Harvey out with his first step, forward (to my right), for each attempt
//this loop represents each attempt to walk across the island.
while(position != 3 && position != -1){
position = walk(ary, row, col, position);
//check position & update status
update(ary, row, col, position, flower, water, safe);
}
}//end for loop
```

It works fine when I leave that code in main(). The other functions work! But when I try to do the same with this code using a function (just like the others?), I get these errors:

invalid conversion from `int (*)[14]' to `int'

initializing argument 1 of `int walk(int, int&, int&, int)'

invalid conversion from `int (*)[14]' to `int'

initializing argument 1 of `void update(int, int&, int&, int, int&, int&, int&)'

This is the function (prototype & definition):

```
void runSim(int, int, int, int);
void runSim(int ary[ROWS][COLS], int flower, int water, int safe){
for(int i = 0; i < 100; i++){
//reset field of flowers for each attempt
populateAry(ary); //I find it ODD that the compiler does not complain about this one!?!
int row = 6, col = 1; //reset position
int position = ary[row][col]; //start Harvey out with his first step, forward (to my right), for each attempt
//this loop represents each attempt to walk across the island.
while(position != 3 && position != -1){
position = walk(ary, row, col, position);
//check position & update status
update(ary, row, col, position, flower, water, safe);
}
}//end for loop
}
```

Here is how it is called from within int main();

`runSim(ary, flower, water, safe);`

And THIS (ugh!) is my entire program:

```
//CS 318
#include<iostream>
#include<fstream>
#include<iomanip>//for setprecision
using namespace std;
//global constant variables
const int ROWS = 13;
const int COLS = 14;
//prototypes
void populateAry(int);
void printAry(int, ofstream&);
void runSim(int, int, int, int);
int walk(int, int&, int&, int);
void update(int, int&, int&, int, int&, int&, int&);
double calcCost(int);
void printResults(int, int, int, double, ofstream&);
//functions
void populateAry(int ary[ROWS][COLS]){
for(int r = 0; r<ROWS; r++){
for(int c = 0; c<COLS; c++){
//add -1's to array (water)
if((r==0 || r==12) || ((c==0 || c==13) && r !=6)){
ary[r][c]= -1;
}
//add 0's (safe path)
else if (r==6 && c!=0 && c!=13){
ary[r][c]= 0;
}
//add 3's (bridge)
else if (r==6 && (c==0 || c==13)){
ary[r][c] = 3;
}
//add 2's (flowers)
else{
ary[r][c]=2;
}
}
}
}
void printAry(int ary[ROWS][COLS], ofstream& outFile){
cout<<endl<<setw(40)<<"Flowers Unlimited Park\n\n";
outFile<<endl<<setw(40)<<"Flowers Unlimited Park\n\n";
for(int r = 0; r<ROWS; r++){
for(int c = 0; c<COLS; c++){
cout<<" "<<ary[r][c];
outFile<<" "<<ary[r][c];
if(ary[r][c] >=0){
cout<<" "; //extra space because of -
outFile<<" ";
}
if(c==13){
cout<<endl;//new line for each row
outFile<<endl;
}
}
}
}
void runSim(int ary[ROWS][COLS], int flower, int water, int safe){
for(int i = 0; i < 100; i++){
//reset field of flowers for each attempt
populateAry(ary);
int row = 6, col = 1; //reset position
int position = ary[row][col]; //start Harvey out with his first step, forward (to my right), for each attempt
//this loop represents each attempt to walk across the island.
while(position != 3 && position != -1){
position = walk(ary, row, col, position);
//check position & update status
update(ary, row, col, position, flower, water, safe);
}
}//end for loop
}
int walk(int ary[ROWS][COLS], int& row, int& col, int pos){
//move it, Harvey!!
int step = rand() % 100 +1;
//decide which way he stepped
if(step <=45){ //forward 45%...which means to MY right.
pos = ary[row][++col];//move him one column to my right
}
else if (step<=70){ //left 25%...UPward
pos = ary[--row][col]; //move him one row up
}
else if (step<=90){ //right 20%...DOWNward
pos = ary[++row][col];
}
else if (step<=100){ //backward 10% ...to MY left
pos = ary[row][--col]; //move him one column left
}
return pos;
}
void update(int ary[ROWS][COLS], int& row, int& col, int pos, int& flower, int& water, int& safe){
//did he step on a flower?
if(pos ==2 || pos ==1){
//subtract one from that element in the array
ary[row][col]-=1;
//add to flower counter
flower++;
}
if(pos == -1){ //he's in the water
water++;
}
if(pos == 3){ //he's safe
safe++;
}
}
double calcCost(int flower){
return double((flower*5.0)/100);
}
void printResults(int water, int safe, int flower, double avg, ofstream& outFile){
cout<<"\n Total number of times Harvey had to be rescued from the water: "<<water
<<".\n\n Total number of times Harvey made it to a bridge: "<<safe
<<".\n\n Total number of flowers Harvey destroyed: "<<flower
<<fixed<<showpoint<<setprecision(2)<<".\n\n Average cost of Harvey's walk: $"<<avg<<endl<<endl;
outFile<<"\n Total number of times Harvey had to be rescued from the water: "<<water
<<".\n\n Total number of times Harvey made it to a bridge: "<<safe
<<".\n\n Total number of flowers Harvey destroyed: "<<flower
<<fixed<<showpoint<<setprecision(2)<<".\n\n Average cost of Harvey's walk: $"<<avg<<endl<<endl;
}
int main(){
system("color e1"); //black & white all the time is kinda boring...
ofstream outFile;
outFile.open("Harvey.txt");
//counters
int water = 0, safe = 0, flower = 0;
int ary[ROWS][COLS];
populateAry(ary);
printAry(ary, outFile); //just to make sure the array has been populated correctly
//attempt to walk across the island--100 times
runSim(ary, flower, water, safe);
double avg = calcCost(flower);
printResults(water, safe, flower, avg, outFile);
outFile.close();
cin.get();
return 0;
}
//Random Walk
//The local town drunk, Harvey, has gotten himself into a mess. Besides
//being in his normal state, a state that earned him his title, he has made
//his way into the Flowers Unlimited Park, a park where many flowers are
//grown and display in their natural beauty. The local ordinance fines
//individuals $5.00 for each flower they pick or destroy. This is enforce
//to insure the beauty and the integrity of the park. Now old Harv is not
//only in the wrong state, drunk, and in the wrong place, the park, he is
//also on a small island within the park, eleven feet wide by 12 feet long.
//The island is connected to the main land by two bridges one at each end
//of the island. Now Harv needs to get off the island and in the process,
//it will cost him (ie stepping on flowers to get off the island).
//There is a clear path down the middle of the island that leads from one
//bridge to another. The remainder of the island has flowers. On the island,
//there are two flowers growing per square foot. What we need to find out
//is how much is it going to cost Old Harv to walk from where he is (the end
//of the bridge on the island (ie first step forward put Harv on the island)
//to either bridge and get off the island?
//After studying Harv for many years, it is known that he doesn't walk a
//straight line when he is in his preferred state. His walking patterns are
//as follows. He steps forward 45% of the time, he steps left 25% of the
//time, right 20% and back wards 10% of the time. If Harvey steps onto
//either bridge, we will consider that he has made it across the island.
//If he steps into the water, he has finished walking and must be rescued.
//If he steps off the path onto a square containing two flowers, he destroys
//one. If he steps into the same square later, he destroys the second flower.
//Write a program that will compute the cost of Harvey's walk in the park.
//
//Inputs: None
//Outputs: The cost (average) of Harvey's walk.
// The number of times Harvey made it to a bridge.
// The number of times Harvey had to be rescued from the water.
//Restrictions: Use a 2-d array. Run the simulation 100 times to generate the results.
//Output: Format output in a readable style. (Columns maybe)
```

*Edited 6 Years Ago by MyrtleTurtle*: n/a