Problem output of function

void find_winner(int array[]){
int i,questions[3],j=0;
for (i=0; i<3; i++){
questions[i]=1;
}
for (i=0; i<3; i++){
while (array[j+1]!=1){
questions[i]++;
j++;
}
}
for (i=0; i<3; i++){
printf("%d",questions[i]);
}
}

This function should find the winner of a game,that is the one that answered at the most questions.For example,if there is an array
[1]
[2]
[3]
[1]
[2]
[1]
[2]
[3]
the first player answered three questions,the second one answered 2 questions and the third one three.so,there are two winners,the player one and the player three.
My problem is that it just prints the number of questions that the first two players answered.What have I done wrong?
I hope someone can help me!!!

not to sound like a smart a$$ but thats what your code should do with the way you have it coded. One way to get it to do what you want it to do would be to have a variable in the second for loop (declared before entering the loop so it is accessible from the third for loop also) that kept track of the most questions answered, then on the third for loop you could have it only print the elements in the array that equaled the variable.

I have tried it with a variable,but it also wasn't accessible from the third loop.Although the last player answered just three questions,the variable I used got the number 22,and it shoulb be 3,at this case :confused:

Shouldn't it be that player 1 answered 3, player 2 answered 3 and player 3 answered 2?

First initialise questions to 0. Loop through array (using i?) and do questions[array[i] - 1]++; This will then give you the scores for the players (assuming array contains values in the range 1 - 3 (you should check). Then just iterate through questions to find the element(s) with the highest score and its index + 1 is(are) the winners. When I get access to my MSVS again I'll knock you up some code. In the meantime I hope this helps.

Try this

Code:

---

#include <iostream>
using namespace std;

#define NO_PLAYER        3

void find_winner(int ans[]) {
int        players[NO_PLAYER] = {0},
        j = 0,
        max = 0;

        while (ans[j] >= 1 && ans[j] <= NO_PLAYER) {
                int pl = ans[j] - 1;
                players[pl]++;

                if (players[pl] > max)
                        max = players[pl];

                j++;
        }

        for (int i = 0; i < NO_PLAYER; i++)
                if (players[i] == max)
                        cout << "player " << i + 1 << " is a winner!" << endl;
}

int main()
{
int answers[] = {1, 2, 3, 1, 2, 1, 2, 3, 0};

        find_winner(answers);
        return 0;
}

---

The end of the answers is indicated by a 0.

Nice,but the numbers of the array answers do not correspond to the players that answer each time a question...
They correspond to the question each player has to answer...For example,if we have the array
answers[] = {1, 2, 3, 4, 5, 6, 1, 1, 2, 0};
the first player answers at 6 question,the second at 1,the third at 2...How can I do this???? :ehh:

Sorry - I misunderstood your question. Do the number sequence always start at 1 and do they increment by 1 until they are reset to 1? So the first 1 corresponds to player 1 and the second 1 corresponds to player 2 etc?

Yes!!!!

OK. Try this.

Code:

---

#include <iostream>
using namespace std;

void find_winner(int ans[]) {
int noplay = 0,
    i = 0,
    pl = -1,
    max = 0;

        while (ans[i] > 0)
                if (ans[i++] == 1)
                        noplay++;

int *play = new int[noplay];

        for (int j = 0; j < noplay; j++)
                play[j] = 0;

        i = 0;
        while (ans[i] > 0) {
                if (ans[i++] == 1)
                        pl++;

                play[pl]++;
                if (play[pl] > max)
                        max = play[pl];
        }

        for (int j = 0; j < noplay; j++)
                if (play[j] == max)
                        cout << "player " << j + 1 << " winner" << endl;

        delete [] play;
}

int main()
{
int answers[] = {1, 2, 3, 1, 2, 1, 2, 3, 0};
//int answers[] = {1, 2, 3, 4, 5, 6, 1, 1, 2, 0};
        find_winner(answers);
        return 0;
}

---

I have runned the program,using this function:

Code:

---

void find_winner(int ans[]) {
int noplay=0,i=0,pl=-1,max=0,*play,j;
    while (ans[i] > 0){
                if (ans[i++] == 1) noplay++;
    }
    printf("%d\n",noplay);
                for (j = 0; j < noplay; j++)
                    play[j] = 0;

        i=0;
        while (ans[i] > 0) {
                  if (ans[i++] == 1)
                          pl++;

                play[pl]++;
                if (play[pl] > max)
                        max = play[pl];
        }

        for (j = 0; j < noplay; j++)
                if (play[j]==max)
                        printf("player %d  winner",j+1);

}

---

but I get a segmentation fault...Why does it happen??? :confused:

Now I runned it using this code:

Code:

---

void find_winner(int ans[]) {
int noplay=0,i=0,pl=-1,max=0,play[3],j;
                for (j = 0; j <3; j++)
                    play[j] = 0;

        i=0;
        while (ans[i] > 0) {
                  if (ans[i++] == 1)
                          pl++;

                play[pl]++;
                if (play[pl] > max)
                        max = play[pl];
        }

        for (j = 0; j <3; j++)
                if (play[j]==max)
                        printf("player %d  winner",j+1);

}

---

I gave at all the players the same number of questions,but the output is just : player 3 winner
How can I change this code so that if all the players are winners that they will all be printed???

You are not using the code I posted! Your code in post #10 fails because play is a pointer to an integer and hasn't been initialised. That's what the new did in my original code.

Your code in post #11 when run on my system produces the output
player 1 winnerplayer 3 winner

Try changing the printf statement to

Code:

---

printf("player %d  winner\n",j+1);

---

Yes,it has a right result if there are two winners,but not if there are 3 :/

If you want to use an array in the function, then the code can be shorted to

Code:

---

void find_winner(int ans[]) {
int        noplay = 0,
        i = 0,
        pl = -1,
        max = 0,
        play[3] = {0},
        j;

        while (ans[i] > 0) {
                if (ans[i++] == 1)
                        pl++;

                play[pl]++;
                if (play[pl] > max)
                        max = play[pl];
        }

        for (j = 0; j < 3; j++)
                if (play[j] == max)
                        printf("player %d  winner\n", j + 1);
}

---

On my system with the input 1, 2, 3, 1, 2, 1, 2, 3, 0 this gives as output

player 1 winner
player 3 winner

Note that if there are more than 3 players, this program will crash! My code in post #9 dealt with an unknown number of players.

Quote:

---

Originally Posted by mathmari

Yes,it has a right result if there are two winners,but not if there are 3 :/

---

With the input of {1, 2, 3, 1, 2, 3, 1, 2, 3, 0}, my program produces

player 1 winner
player 2 winner
player 3 winner

What input data are you using for which the program produces incorrect output?

I give these values(the same like you):
1
2
3
1
2
3
1
2
3
but I get the result player 3 winner :(

I gave the values:
1
2
3
1
2
3
1
2
3
but I just get the result player 3 winner :(

Quote:

---

Originally Posted by mathmari

I gave the values:
1
2
3
1
2
3
1
2
3
but I just get the result player 3 winner :(

---

What about the terminating 0? The program will continue reading data until it finds the 0. If there is no terminating 0 specified the program will read data until it finds one somewhere in memory - which will make player 3 always the winner!

If you want to use a fixed size matrix for play - rather than dynamically allocated at run time - then the code below will check for array bound overflow. Note the final terminating 0 in the test data in main.

There must be someway for find_winner to know when the end of array ans is reached. I've used 0 as the terminating number. Another way of doing this would be to have an extra parameter to find_winner that specifies the number of elements in array ans. However, this could be prone to error. IMO having a terminating 0 is preferable.

Code:

---

#include <stdio.h>

#define NO_PLAYER        3

void find_winner(int ans[]) {
int        noplay = 0,
        i = 0,
        pl = -1,
        max = 0,
        j,
        play[NO_PLAYER] = {0};

        while (ans[i] > 0) {
                if (ans[i++] == 1)
                        if (++pl >= NO_PLAYER)
                                break;

                play[pl]++;
                if (play[pl] > max)
                        max = play[pl];
        }

          for (j = 0; j < NO_PLAYER; j++)
                if (play[j] == max)
                        printf("player %d  winner\n", j + 1);
}

int main()
{
int answers[] = {1, 2, 3, 1, 2, 3, 1, 2, 3, 0};

        find_winner(answers);
        return 0;
}

---

This code produces the output
player 1 winner
player 2 winner
player 3 winner

Thank you veeery much!!!!!!!!! :thumb: