python/TangDou/XiTi/1256.cpp

#include <bits/stdc++.h>

using namespace std;
/*
测试用例：

4 5
1 5
5 2
3 4
2 3

答案：3
*/
int n, m;
const int N = 1e5 + 10;
int w[N];
int main() {
    cin >> n >> m;
    w[1] = 1; // 1号碗里放小球

    for (int i = 1; i <= n; i++) {
        int x, y;
        cin >> x >> y;
        swap(w[x], w[y]);
    }
    for (int i = 1; i <= m; i++)
        if (w[i]) {
            printf("%d\n", i);
            break;
        }

    return 0;
}