Magic Trick - Live Archive 3154 AC

#include <stdio.h>
#include <algorithm>
#include <string.h>
using namespace std;

char val[] = {'1','2','3','4','5',
    '6','7','8','9','T','J','Q','K'};
char suit[] = {'H', 'C', 'D', 'S'};

struct card {
    int v,s;

    bool operator==(card& a) {
        return this->s==a.s && this->v==a.v;
    }
};

int t;
card cs[4];

void read(card& a) {
    char tmp[5];
    scanf(" %s", tmp);

    for (int i=0; i<13; i++)
        if (tmp[0]==val[i])
            a.v=i;

    for (int i=0; i<4; i++)
        if (tmp[1]==suit[i])
            a.s=i;
}

bool cmp(card a, card b) {
    if (a.s==b.s)
        return a.v<b.v;
    return a.s<b.s;
}

int compare() {
    card ord[3];
    int p[3] = {0,1,2};
    int cnt=1;

    for (int i=0; i<3; i++)
        ord[i]=cs[i+1];

    sort(ord,ord+3,cmp);

    do {
        if (cs[1]==ord[p[0]] &&
            cs[2]==ord[p[1]] &&
            cs[3]==ord[p[2]])
        return cnt;
        cnt++;
    } while (next_permutation(p,p+3));

    return cnt;
}

int main() {
    scanf("%d", &t);

    while (t--) {
        for (int i=0; i<4; i++)
            read(cs[i]);

        int vC = (cs[0].v+compare())%13;
        printf("%c%c\n", val[vC],suit[cs[0].s]);
    }
    return 0;
}