题目链接:bnu 34982 Beautiful Garden
题目大意:给定一个长度为n的序列,问说最少移动多少点,使得序列成等差序列,点的位置能够为小数。
解题思路:算是纯暴力吧。枚举等差的起始和中间一点,由于要求定中间一点的位置。所以这一步是o(n3);然后用o(n)的算法确定说须要移动几个来保证序列等差。
#include <cstdio>
#include <cstring>
#include <vector>
#include <algorithm>
using namespace std;
const int N = 1e5+5;
bool flag;
int n, m, c, mv, f[N], r[N], ans[N];
vector<int> g[N];
int getfar(int x) {
return x == f[x] ? x : f[x] = getfar(f[x]);
}
void init () {
scanf("%d%d", &n, &m);
flag = false;
for (int i = 0; i <= n; i++)
r[i] = f[i] = i;
for (int i = 0; i < m; i++)
g[i].clear();
int t;
for (int i = 0; i < m; i++) {
scanf("%d", &t);
int a, pre = 0;
for (int j = 0; j < t; j++) {
scanf("%d", &a);
g[i].push_back(a);
if (a < pre)
flag = true;
pre = a;
}
}
}
bool insert (int x, int d) {
for (int j = mv-1; j >= 0; j--) {
if (g[d][j] < x) {
int p = getfar(g[d][j]);
f[p] = x;
r[p] = x;
mv = j;
return true;
}
}
return false;
}
void put(int x) {
ans[c--] = x;
if (r[x] != x)
put(r[x]);
}
void solve () {
for (int i = m-1; i; i--) {
int t = g[i].size();
mv = g[i-1].size();
for (int j = t-1; j >= 0; j--)
if (!insert(g[i][j], i-1)) {
flag = true;
return;
}
}
c = n;
int t = g[0].size();
for (int i = t-1; i >= 0; i--)
put(g[0][i]);
}
int main () {
int cas;
scanf("%d", &cas);
for (int i = 1; i <= cas; i++) {
init ();
printf("Case #%d: ", i);
solve();
if (flag) {
printf("No solution\n");
} else {
for (int j = 1; j < n; j++)
printf("%d ", ans[j]);
printf("%d\n", ans[n]);
}
}
return 0;
}
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时间: 2024-10-29 19:11:36