c/c++语言开发共享洛谷P4704 太极剑(乱搞)

题意

题目链接

sol

不会正解

写了发暴力过了，貌似跑的还挺快？。。

// luogu-judger-enable-o2 // luogu-judger-enable-o2 #include<bits/stdc++.h>  #define mp(x, y) make_pair(x, y) #define fi first #define se second #define ll long long template <typename a, typename b> inline bool chmin(a &a, b b){if(a > b) {a = b; return 1;} return 0;} template <typename a, typename b> inline bool chmax(a &a, b b){if(a < b) {a = b; return 1;} return 0;} #define getchar() (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 1<<22, stdin), p1 == p2) ? eof : *p1++) char buf[(1 << 22)], *p1 = buf, *p2 = buf; using namespace std; const int maxn = 8e5 + 10, inf = 1e9; const double eps = 1e-5; inline int read() {     char c = getchar(); int x = 0, f = 1;     while(c < '0' || c > '9') {if(c == '-') f = -1; c = getchar();}     while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();     return x * f; } int n, a[maxn], b[maxn], col[maxn], out, x, y, gg = inf, ti[maxn], ss, st[maxn], top; int solve(int l, int r) {     ss++;     int ans = 0;     for(int i = l; i <= r; i++) {         if(ti[col[i]] != ss) ti[col[i]] = ss;         else ans++, ss++;         if(ans >= out) return out;     }     return ans; } signed main() {     n = read();     for(int i = 1; i <= n; i++) {         a[i] = read(), b[i] = read();         if(a[i] > b[i]) swap(a[i], b[i]);         col[a[i]] = col[a[i] + 2 * n] = i;         col[b[i]] = col[b[i] + 2 * n] = i;         int tmp = min(b[i] - a[i], a[i] - b[i] + 2 * n);         if(tmp < gg) x = a[i], y = b[i], gg = tmp;     }     out = inf;     for(int i = x; i <= y; i++) st[++top] = i;     random_shuffle(st + 1, st + top + 1);     for(int i = 1; i <= top; i++) {         int k = st[i];         chmin(out, solve(k, k + 2 * n - 1));     }     cout << out / 2 +1;     return 0; }