最小变更量c ++

Question

I need to give the minimum amount of change possible.I input number of cases,each case had a number of coins(1 is not necessarily a part of them) and the number of number I want to test.Then I enter the different coins and the different number to test.

I dont know why my program isnt working.Since 1 isnt necessarily part of the change,I had to tweak the program a little.

#include "stdafx.h"
#include<iostream>
#include<conio.h>
#include<functional>
#include<numeric>
#include<algorithm>
#include<vector>

using namespace std;



int main()
{
    int n,i;
    cin>>n;
    int f=n,c,m;
    int flag=0;
    int m1;
    int coins[100];
    vector <int>storage(100,0);
    vector <int> testcases(1000,0);
    vector <int> answers(1000,-1);

    while(n>0)
    {
        cin>>c;
        cin>>m;
        for(i=1;i<=c;i++)
        {
            cin>>coins[i];
        }
        for(i=1;i<=c;i++)
        {
            cin>>testcases[i];
        }
        m1=*max_element(testcases.begin(),testcases.end());
        for(i=0;i<1000;i++)
        {
            answers[i]=-1;
        }


            i=0;
            while(m1>=i)
            {
                i++;
                flag=0;

            for(int j=1;j<=c;j++)
            {
                if(i-coins[j]>=0)
                {
                    storage[j]=answers[i-coins[j]];
                    flag=1;
                }
                else
                storage[j]=-2;

            }
            if(flag==1)
            {answers[i]=*min_element(begin(storage), end(storage),
    [](int t1, int t2) {return t1 > 0 && (t2 <= 0 || t1 < t2);});

            flag=0;
            }
            else
                answers[i]=0;


            }

            if(m1==i)
            {
                for(int y=1;y<=m;y++)
                {
                    cout<<answers[testcases[y]]<<endl;
                }
            }

    }


return 0;
}

EDIT: By "not working" I mean its actually doesnt do anything.Its takes input and does nothing.I think it goes into an infinite loop.

Answer 1

Universal solution: Run your app under debugger. Step into the code, then watch values of variables. Compare with values that you expect. Try to edit code, re-compile, and debug again. Place a breakpoints in problem places to quickly jump through the code.

I see #include "stdafx.h" , that probably means that you using Visual Studio. Here is a guide:

Mastering Debugging in Visual Studio 2010 - A Beginner's Guide

Answer 2

There could be lots of things wrong with this code (I didn't test it) but one simple problem which would cause an infinite loop is this

while (n > 0)
{
    // lots of code which never changes n
}

You have an infinite loop because nowhere inside the while (n > 0) loop do you modify the value of n .

I would guess you want this

while (n > 0)
{
    // lots of code which never changes n
    --n;
}