UVA

挺好的思路题， 题解紫书249页写的很明白，不过推荐自己先想一下

#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>#include <vector>using namespace std;typedef pair<int, int> P;const int maxn = 1300;bool vis[maxn];char str[maxn][maxn];int n, a[maxn][maxn];int cnt, pos[maxn];vector<P> match[maxn];int main() {    int change[maxn];    change[2] = 1, change[4] = 2, change[8] = 3, change[16] = 4, change[32] = 5;    change[64] = 6, change[128] = 7, change[256] = 8, change[512] = 9, change[1024] = 10;    while (~scanf("%d", &n)) {        for (int i = 1; i <= n; i++) scanf("%s", str[i] + 1);        int m = change[n];        memset(vis, false, sizeof(vis));        memset(a, 0, sizeof(a));        for (int i = 0; i <= m; i++) match[i].clear();        for (int i = 1; i <= n; i++) {            for (int j = 1; j <= n; j++) {                a[i][j] = str[i][j] - '0';            }        }        for (int k = 1; k <= m; k++) {            //step1:            for (int i = 1; i <= n; i++) {                if (vis[i] || a[1][i]) continue;                for (int j = 1; j <= n; j++) {                    if (vis[j] || !a[j][i] || !a[1][j]) continue;                    vis[i] = vis[j] = true;                    match[k].push_back(make_pair(j, i));                    break;                }            }            //step2:            for (int i = 2; i <= n; i++) {                if (vis[i] || !a[1][i]) continue;                match[k].push_back(make_pair(1, i));                vis[i] = true; break;            }            //step3:            cnt = 0;            for (int i = 2; i <= n; i++) {                if (vis[i] || a[1][i]) continue;                pos[++cnt] = i;            }            for (int i = 1; i < cnt; i+=2) {                vis[pos[i]] = vis[pos[i+1]] = true;                if (!a[pos[i]][pos[i + 1]]) swap(pos[i], pos[i + 1]);                match[k].push_back(make_pair(pos[i], pos[i + 1]));            }            //step4:            cnt = 0;            for (int i = 2; i <= n; i++) {                if (!vis[i]) pos[++cnt] = i;            }            for (int i = 1; i <= cnt; i+=2) {                vis[pos[i]] = vis[pos[i + 1]] = true;                if (!a[pos[i]][pos[i+1]]) swap(pos[i], pos[i + 1]);                match[k].push_back(make_pair(pos[i], pos[i + 1]));            }            //last            for (unsigned int i = 0; i < match[k].size(); i++) {                int index = match[k][i].first;                vis[index] = false;            }        }        for (int i = 1; i <= m; i++) {            for (unsigned int j = 0; j < match[i].size(); j++) {                printf("%d %d\n", match[i][j].first, match[i][j].second);            }        }    }    return 0;}