uva 10596(欧拉路)

来源：互联网发布：三菱fx编程手册编辑：程序博客网时间：2024/06/09 16:43

题解：并查集判断是否连通，然后判断是否为欧拉路，是不是所有的结点度数都是偶数，注意R == 0的时候输出NOT

#include <stdio.h>#include <string.h>const int N = 200 + 5;int du[N], flag, n, r, pa[N], vis[N];void init() {    memset(du, 0, sizeof(du));    memset(vis, 0, sizeof(vis));    for (int i = 0; i < n; i++)        pa[i] = i;    flag = 0;}int get_parent(int x) {    return pa[x] == x ? x : get_parent(pa[x]);}void Union(int x, int y) {    vis[x] = vis[y] = 1;    int px = get_parent(x);    int py = get_parent(y);    if (px != py)        pa[px] = pa[py];}void judge() {    int num = 0;    for (int i = 0; i < n; i++)        if (vis[i] && pa[i] == i)            num++;    if (num > 1)        flag = 1;}void judge1() {    for (int i = 0; i < n; i++)        if (vis[i] && du[i] % 2 != 0) {            flag = 1;            break;        }}int main() {    int v1, v2;    while (scanf("%d %d", &n, &r) != EOF) {        if (r == 0) {            printf("Not Possible\n");            continue;        }        init();        while (r--) {            scanf("%d%d", &v1, &v2);            du[v1]++;            du[v2]++;            Union(v1, v2);        }        judge();        if (flag)            printf("Not Possible\n");        else {            judge1();            if (flag)                printf("Not Possible\n");            else                printf("Possible\n");        }    }    return 0;}

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