P1076 [NOIP 2012 普及组] 寻宝

#include <cstdio>
#include <algorithm>

using namespace std;

const int maxn = 1e6 + 5, mod = 20123;

struct Room {
    bool f = false;
    int x;
};

Room room[10005][105];
int n, m, s, cnt_f[10005];
void Input() {
    scanf("%d %d", &n, &m);
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) {
            int a, x;
            scanf("%d %d", &a, &x);
            if (a == 1) {
                room[i][j].f = true;
                ++cnt_f[i];
            }
            room[i][j].x = x;
        }
    }
    scanf("%d", &s);
    ++s;
}

int v[10005][105];
void Init() {
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) {
            int x = room[i][j].x;
            int nx = x % cnt_f[i];
            if (nx == 0) {
                nx = cnt_f[i];
            }
            int p = j, cnt = 0;
            while (true) {
                if (room[i][p].f) {
                    cnt++;
                    if (cnt == nx) {
                        break;
                    }
                }
                p = p % m + 1;
            }
            v[i][j] = p;
        }
    }
}

int sum, p;
void GO() {
    p = s;
    for (int i = 1; i <= n; ++i) {
        sum += room[i][p].x;
        p = v[i][p];
    }
    sum %= mod;
}

int main() {
    Input();
    Init();
    GO();
    printf("%d", sum % mod);
    return 0;
}