标签：长度 ide cli code col return break 替换 size
A.给你一个字符串 复制K-1次首尾相接 每次你可以把任意位置的字符替换成任意一个 问你最少替换几次可以使得复制后的串任意两个相邻的字符不同
解:一段长度为x的相同字符 要满足条件需要x/2次替换
#include<bits/stdc++.h> using namespace std; typedef long long ll; int main() { string a; cin >> a; ll k; cin >> k; int len = a.size(); if (len == 1) { cout << k / 2 << endl; } else if (len == 2) { if (a[0] == a[1]) { cout << k << endl; } else { cout << 0 << endl; } } else { bool flg = 1; for (int i = 1; i < len; i++) { if (a[i] != a[0]) { flg = 0; break; } } if (flg) { cout << 1LL * len * k / 2 << endl; return 0; } ll ans = 0; char ch = ‘0‘; int now = 0; for (int i = 0; i <= len; i++) { if (i == len || a[i] != ch) { ans += now / 2; ch = a[i]; now = 1; continue; } now++; } int l = 0, r = 0; if (a[0] == a[len - 1]) { for (l = 0; l < len; l++) if (a[l] != a[0]) { l--; break; } for (r = len - 1; r >= 0; r--) if (a[r] != a[0]) { r++; break; } r = len - r; l++; ans -= l / 2 + r / 2; } ans *= k; ans += 1LL * (l + r) / 2 * (k - 1); ans += l / 2 + r / 2; cout << ans << endl; } }
B.给你一个连通图 问你最多能把这个图分成几层(同层之间的点不能有边 类似于X分图)
解:直接暴力从每个点开始BFS即可
#include<bits/stdc++.h> using namespace std; typedef long long ll; vector<int> g[205]; char f[205]; int du[205]; int lev[205]; bool vis[205]; int main() { int n; scanf("%d", &n); for (int i = 1; i <= n; i++) { scanf("%s", f + 1); for (int j = i + 1; j <= n; j++) { if (f[j] == ‘1‘) { g[i].push_back(j); g[j].push_back(i); du[i]++, du[j]++; } } } queue<int> que; bool flag = 1; int ans = -1; for (int i = 1; i <= n; i++) { //cout << "do " << i << endl; fill_n(lev, n + 2, 0); fill_n(vis, n + 2, 0); flag = 1; int ansnow = -1; while (que.size()) { que.pop(); } que.push(i); lev[i] = 1; while (que.size() && flag) { int x = que.front(); //cout << x << " " << lev[x] << endl; que.pop(); vis[x] = 1; for (int v : g[x]) { if (lev[v] == 0) { lev[v] = lev[x] + 1; ansnow = max(ansnow, lev[v]); que.push(v); } else if (lev[v] == lev[x] || abs(lev[v] - lev[x]) >= 2) { flag = 0; break; } else if (abs(lev[v] - lev[x]) == 1) { if (lev[v] < lev[x] && !vis[v]) { flag = 0; break; } if (lev[v] > lev[x] && vis[v]) { flag = 0; break; } } } } if (flag) { ans = max(ans, ansnow); } } cout << ans << endl; }
标签：长度 ide cli code col return break 替换 size
原文地址：https://www.cnblogs.com/Aragaki/p/11756210.html
