uva 12356 Army Buddies

简单的并查集应用。

#include<stdio.h>

#include<string.h>

#include<math.h>

#include<algorithm>

using namespace std;

const int maxn = 100000 + 10;

int ll[maxn], rr[maxn];

int f1(int x)

{

    if (x != ll[x]) ll[x] = f1(ll[x]);

    return ll[x];

}

int f2(int x)

{

    if (x != rr[x]) rr[x] = f2(rr[x]);

    return rr[x];

}

int main()

{

    int n, m, i, a, b, j;

    while (~scanf("%d%d", &n, &m))

    {

        if (n == 0 && m == 0) break;

        for (i = 0; i <= n; i++) ll[i] = i, rr[i] = i;

        for (i = 0; i < m; i++)

        {

            scanf("%d%d", &a, &b);
　　　　　　　for (j = a; j <= b; j++) ll[j] = a;

            ll[a] = a - 1;

            for (j = a; j <= b; j++) rr[j] = b;

            rr[b] = b + 1;

            int zuo = f1(a);

            int you = f2(b);

            if (zuo == 0 || zuo == n + 1) printf("* ");

            else printf("%d ", zuo);

            if (you == n + 1 || you == 0) printf("*\n");

            else printf("%d\n", you);

        }

        printf("-\n");

    }

    return 0;

}