Mastermind EXAM05

#include<stdio.h>
void inttochar(char now[],int I){
    for(int i=0;i<=3;i++)now[i] = '0';now[4] = '\0';
        int ti = I;int nin = 3;
        while(ti!=0){
            now[nin--] = (ti%10)+'0';
            ti/=10;
    }
}

int main()
{
    int m;
    scanf("%d",&m);
    char tries[m][5];
    int PosC[m];
    int NumC[m];
    for(int i=0;i<m;i++){
        scanf("%s",tries[i]);
        scanf("%d %d",&PosC[i],&NumC[i]);
    }
    for(int i=0;i<=9999;i++){
        char now[5];
        inttochar(now,i);
        bool possible = true;
        for(int j=0;j<m && possible;j++){
            int countpos = 0;
            for(int k=0;k<4;k++){
                if(now[k] == tries[j][k]){
                    countpos++;
                }
            }
            if(countpos != PosC[j])possible = false;

            if(possible){
                int checkNum[10];for(int i=0;i<10;i++)checkNum[i] = 0;
                for(int k=0;k<4;k++){
                    checkNum[tries[j][k] - '0']++;
                }
                int countNum = 0;
                for(int k=0;k<4;k++){
                    if(checkNum[now[k] - '0'] > 0){
                        countNum++;
                        checkNum[now[k] - '0']--;
                    }
                }
                if(countNum-countpos != NumC[j])possible = false;
            }

        }

        if(possible)
            printf("%s\n",now);
    }
}