看哪一維是偶數,答案是0,不然是三個數兩兩組合相乘中最小的那個node
#include <bits/stdc++.h> #define fi first #define se second #define pii pair<int,int> #define mp make_pair #define pb push_back #define space putchar(' ') #define enter putchar('\n') #define eps 1e-10 #define MAXN 1000005 //#define ivorysi using namespace std; typedef long long int64; typedef unsigned int u32; typedef double db; template<class T> void read(T &res) { res = 0;T f = 1;char c = getchar(); while(c < '0' || c > '9') { if(c == '-') f = -1; c = getchar(); } while(c >= '0' && c <= '9') { res = res * 10 +c - '0'; c = getchar(); } res *= f; } template<class T> void out(T x) { if(x < 0) {x = -x;putchar('-');} if(x >= 10) { out(x / 10); } putchar('0' + x % 10); } int A,B,C; void Solve() { read(A);read(B);read(C); if(A % 2 == 0 || B % 2 == 0 || C % 2 == 0) {out(0);enter;} else { out(min(min(1LL * A * B,1LL * B * C),1LL * A * C));enter; } } int main() { #ifdef ivorysi freopen("f1.in","r",stdin); #endif Solve(); return 0; }
枚舉第二種操做的次數是k,每一個slime得到的時間能夠成爲前k個(循環)中最小的那個時間c++
#include <bits/stdc++.h> #define fi first #define se second #define pii pair<int,int> #define mp make_pair #define pb push_back #define space putchar(' ') #define enter putchar('\n') #define eps 1e-10 #define MAXN 2005 //#define ivorysi using namespace std; typedef long long int64; typedef unsigned int u32; typedef double db; template<class T> void read(T &res) { res = 0;T f = 1;char c = getchar(); while(c < '0' || c > '9') { if(c == '-') f = -1; c = getchar(); } while(c >= '0' && c <= '9') { res = res * 10 +c - '0'; c = getchar(); } res *= f; } template<class T> void out(T x) { if(x < 0) {x = -x;putchar('-');} if(x >= 10) { out(x / 10); } putchar('0' + x % 10); } int N,len[MAXN * 2]; int64 x,a[MAXN * 2],st[MAXN * 2][15]; int64 query(int l,int r) { int t = len[r - l + 1]; return min(st[l][t],st[r - (1 << t) + 1][t]); } void Solve() { read(N);read(x); for(int i = 1 ; i <= N ; ++i) {read(a[i]);a[i + N] = a[i];st[i][0] = a[i];st[i + N][0] = a[i];} for(int j = 1 ; j <= 13 ; ++j) { for(int i = 1 ; i <= 2 * N ; ++i) { if(i + (1 << j) - 1 > 2 * N) break; st[i][j] = min(st[i][j - 1],st[i + (1 << j - 1)][j - 1]); } } for(int i = 2 ; i <= 2 * N ; ++i) len[i] = len[i / 2] + 1; int64 ans = 1e18; for(int i = 0 ; i <= N ; ++i) { int64 tmp = i * x; for(int j = 1 ; j <= N ; ++j) { tmp += query(j + N - i,j + N); } ans = min(ans,tmp); } out(ans);enter; } int main() { #ifdef ivorysi freopen("f1.in","r",stdin); #endif Solve(); return 0; }
直接最上列藍色,最下列紅色,中間奇數列(除了頂端和底端)紅色,偶數列藍色,再把紫色的分配給兩個,這時候必定兩個都連通且只有紫色部分重合ide
#include <bits/stdc++.h> #define fi first #define se second #define pii pair<int,int> #define mp make_pair #define pb push_back #define space putchar(' ') #define enter putchar('\n') #define eps 1e-10 #define MAXN 505 //#define ivorysi using namespace std; typedef long long int64; typedef unsigned int u32; typedef double db; template<class T> void read(T &res) { res = 0;T f = 1;char c = getchar(); while(c < '0' || c > '9') { if(c == '-') f = -1; c = getchar(); } while(c >= '0' && c <= '9') { res = res * 10 +c - '0'; c = getchar(); } res *= f; } template<class T> void out(T x) { if(x < 0) {x = -x;putchar('-');} if(x >= 10) { out(x / 10); } putchar('0' + x % 10); } int H,W; char s[MAXN][MAXN]; char a[MAXN][MAXN],b[MAXN][MAXN]; void Solve() { read(H);read(W); for(int i = 1 ; i <= H ; ++i) scanf("%s",s[i] + 1); for(int i = 1 ; i <= H ; ++i) { for(int j = 1 ; j <= W ; ++j) { a[i][j] = b[i][j] = s[i][j]; } } for(int i = 1 ; i <= W ; ++i) {a[1][i] = '#';b[H][i] = '#';} for(int j = 1 ; j <= W ; ++j) { if(j & 1) { for(int i = 1 ; i < H ; ++i) a[i][j] = '#'; } else { for(int i = 2 ; i <= H ; ++i) b[i][j] = '#'; } } for(int i = 1 ; i <= H ; ++i) { for(int j = 1 ; j <= W ; ++j) { putchar(a[i][j]); } enter; } enter; for(int i = 1 ; i <= H ; ++i) { for(int j = 1 ; j <= W ; ++j) { putchar(b[i][j]); } enter; } } int main() { #ifdef ivorysi freopen("f1.in","r",stdin); #endif Solve(); return 0; }
初始是一個基環內向樹,若是有一個環大於1不管如何存在一個點使得k步以後不在1,因而把1的邊連向本身,而後就變成了一棵樹,dp,每遇到大於k步的時候都把那個點的邊直接連到1便可函數
#include <bits/stdc++.h> #define fi first #define se second #define pii pair<int,int> #define mp make_pair #define pb push_back #define space putchar(' ') #define enter putchar('\n') #define eps 1e-10 #define MAXN 100005 //#define ivorysi using namespace std; typedef long long int64; typedef unsigned int u32; typedef double db; template<class T> void read(T &res) { res = 0;T f = 1;char c = getchar(); while(c < '0' || c > '9') { if(c == '-') f = -1; c = getchar(); } while(c >= '0' && c <= '9') { res = res * 10 +c - '0'; c = getchar(); } res *= f; } template<class T> void out(T x) { if(x < 0) {x = -x;putchar('-');} if(x >= 10) { out(x / 10); } putchar('0' + x % 10); } struct node { int to,next; }E[MAXN * 2]; int N,K,head[MAXN],sumE; int a[MAXN],ans; int rem[MAXN]; void add(int u,int v) { E[++sumE].to = v; E[sumE].next = head[u]; head[u] = sumE; } void dfs(int u) { for(int i = head[u] ; i ; i = E[i].next) { int v = E[i].to; dfs(v); if(rem[v] == K - 1 && u != 1) {++ans;rem[v] = -1;} rem[u] = max(rem[u],rem[v] + 1); } } void Solve() { read(N);read(K); for(int i = 1 ; i <= N ; ++i) { read(a[i]); } if(a[1] != 1) ++ans; for(int i = 2 ; i <= N ; ++i) { add(a[i],i); } dfs(1); out(ans);enter; } int main() { #ifdef ivorysi freopen("f1.in","r",stdin); #endif Solve(); return 0; }
設\(dp[i][j][k][t]\)表示Exit向上最多延伸i,向下最多延伸k,向左最多延伸j,向右最多延伸tspa
此時下邊i行,上面k行,左邊t列,右邊j列,全都不合法,若是咱們要向上下左右擴展某一行某一列,那麼須要在合法的區域內選擇這一行或這一列的機器人個數code
#include <bits/stdc++.h> #define fi first #define se second #define pii pair<int,int> #define mp make_pair #define pb push_back #define space putchar(' ') #define enter putchar('\n') #define eps 1e-10 #define MAXN 100005 //#define ivorysi using namespace std; typedef long long int64; typedef unsigned int u32; typedef double db; template<class T> void read(T &res) { res = 0;T f = 1;char c = getchar(); while(c < '0' || c > '9') { if(c == '-') f = -1; c = getchar(); } while(c >= '0' && c <= '9') { res = res * 10 +c - '0'; c = getchar(); } res *= f; } template<class T> void out(T x) { if(x < 0) {x = -x;putchar('-');} if(x >= 10) { out(x / 10); } putchar('0' + x % 10); } int H,W; char s[105][105]; int sum[105][105],a,b; int dp[2][105][105][105],ans; int query(int x1,int y1,int x2,int y2) { x2 = min(H,x2);y2 = min(W,y2); if(x1 > x2 || y1 > y2) return 0; return sum[x2][y2] - sum[x2][y1 - 1] - sum[x1 - 1][y2] + sum[x1 - 1][y1 - 1]; } void update(int &x,int y) { x = max(x,y); } void Solve() { read(H);read(W); for(int i = 1 ; i <= H ; ++i) scanf("%s",s[i] + 1); for(int i = 1 ; i <= H ; ++i) { for(int j = 1 ; j <= W ; ++j) { sum[i][j] = (s[i][j] == 'o'); sum[i][j] += sum[i][j - 1]; if(s[i][j] == 'E') {a = i;b = j;} } } for(int i = 1 ; i <= H ; ++i) { for(int j = 1 ; j <= W ; ++j) { sum[i][j] += sum[i - 1][j]; } } int cur = 0; dp[0][0][0][0] = 0; for(int i = 0 ; i < a ; ++i) { memset(dp[cur ^ 1],0,sizeof(dp[cur ^ 1])); for(int j = 0 ; j < b ; ++j) { for(int k = 0 ; k <= H - a ; ++k) { for(int t = 0 ; t <= W - b ; ++t) { ans = max(ans,dp[cur][j][k][t]); int tmp = dp[cur][j][k][t]; if(k < a - i - 1) tmp += query(a - i - 1,max(b - j,t + 1),a - i - 1,min(b + t,W - j)); update(dp[cur ^ 1][j][k][t],tmp); tmp = dp[cur][j][k][t]; if(t < b - j - 1) tmp += query(max(a - i,k + 1),b - j - 1,min(a + k,H - i),b - j - 1); update(dp[cur][j + 1][k][t],tmp); tmp = dp[cur][j][k][t]; if(H - i >= a + k + 1) tmp += query(a + k + 1,max(b - j,t + 1),a + k + 1,min(b + t,W - j)); update(dp[cur][j][k + 1][t],tmp); tmp = dp[cur][j][k][t]; if(W - j >= b + t + 1) tmp += query(max(a - i,k + 1),b + t + 1,min(a + k,H - i),b + t + 1); update(dp[cur][j][k][t + 1],tmp); } } } cur ^= 1; } out(ans);enter; } int main() { #ifdef ivorysi freopen("f1.in","r",stdin); #endif Solve(); return 0; }
十分鐘內輕鬆水過1500(我吊打yutaka了),痛罵出題人竟然給這麼簡單的部分分1500而後E題1400?肝E註定失敗?ci
而後開始水基環樹,大膽猜結論以爲斷邊可行,可是樣例告訴我奇環不行,偶環過了不少可是沒全過(用assert判的奇環偶環)rem
實際上轉化一下問題,樹確定是個二分圖,咱們把它二分圖染色,咱們要作的就是把初始的染黑和染白交換位置,若是黑白個數不相等確定不行get
而後咱們只須要一個簡單的dp從下往上計算就能夠了it
對於偶環樹呢,咱們抽出環中的一條邊\((u\rightarrow v)\)而後認爲這個邊上走過的黑色標記有x個(x是負的那麼就是從v到u)
每條邊走過的黑色節點均可以用含x的代數式表示,答案是取某個x這些代數式絕對值和的最小值
是個凹函數,能夠三分
對於奇環樹呢,咱們至關於多了兩個操做,就是選出環上的一條邊做爲特殊邊,邊上相鄰兩點能夠刪掉兩個標記或者同時增長兩個標記
記錄下環上每一個點缺乏多少,而後從兩個端點分別讓這些標記開始走便可
#include <bits/stdc++.h> #define fi first #define se second #define pii pair<int,int> #define mp make_pair #define pb push_back #define space putchar(' ') #define enter putchar('\n') #define eps 1e-10 #define MAXN 100005 //#define ivorysi using namespace std; typedef long long int64; typedef unsigned int u32; typedef double db; template<class T> void read(T &res) { res = 0;T f = 1;char c = getchar(); while(c < '0' || c > '9') { if(c == '-') f = -1; c = getchar(); } while(c >= '0' && c <= '9') { res = res * 10 +c - '0'; c = getchar(); } res *= f; } template<class T> void out(T x) { if(x < 0) {x = -x;putchar('-');} if(x >= 10) { out(x / 10); } putchar('0' + x % 10); } struct node { int to,next; }E[MAXN * 2]; int N,head[MAXN],sumE,M,fa[MAXN],dep[MAXN],st,ed; int64 dp[MAXN][2],ans; bool vis[MAXN]; int c[MAXN],tot,col[MAXN],rec[2],ned[MAXN]; pii val[MAXN]; vector<pii > f; vector<int> dfn; void add(int u,int v) { E[++sumE].to = v; E[sumE].next = head[u]; head[u] = sumE; } void dfs(int u) { dp[u][0] = 1; for(int i = head[u] ; i ; i = E[i].next) { int v = E[i].to; if(v != fa[u]) { fa[v] = u; dfs(v); ans += dp[v][0] + dp[v][1]; dp[u][0] += dp[v][1]; dp[u][1] += dp[v][0]; } } int t = min(dp[u][0],dp[u][1]); dp[u][0] -= t;dp[u][1] -= t; } void find_circle(int u) { dep[u] = dep[fa[u]] + 1; vis[u] = 1; dfn.pb(u); for(int i = head[u] ; i ; i = E[i].next) { int v = E[i].to; if(!vis[v]) { fa[v] = u; col[v] = col[u] ^ 1; find_circle(v); } else if(dep[v] < dep[u] && v != fa[u]) { st = u;ed = v; } } } int64 Calc(int64 x) { int64 res = 0; for(auto t : f) { res += abs(t.fi * x + t.se); } return res; } void EvenCircle() { for(int i = dfn.size() - 1 ; i >= 0 ; --i) { int u = dfn[i]; pii p = val[u]; if(u == st) { f.pb(mp(1,0)); p.fi -= 1; } else if(u == ed) p.fi += 1; if(col[u] == 0) p.se--; else p.se++; if(fa[u]) { f.pb(p); val[fa[u]].fi += p.fi;val[fa[u]].se += p.se; } } int64 L = -N,R = N; while(R - L >= 3) { int64 Lb = L + (R - L) / 3; int64 Rb = R - (R - L) / 3; if(Calc(Lb) > Calc(Rb)) L = Lb; else R = Rb; } int64 res = 1e18; for(int64 i = L ; i <= R ; ++i) res = min(res,Calc(i)); out(res);enter; } void Calc_need(int u) { if(col[u]) ned[u] = -1; else ned[u] = 1; vis[u] = 1; for(int i = head[u] ; i ; i = E[i].next) { int v = E[i].to; if(!vis[v]) { Calc_need(v); ans += abs(ned[v]); ned[u] += ned[v]; } } } void OddCircle() { int64 add = (rec[1] - rec[0]) / 2; memset(vis,0,sizeof(vis)); for(int i = 1 ; i <= tot ; ++i) { vis[c[i]] = 1; } for(int i = 1 ; i <= tot ; ++i) { Calc_need(c[i]); } ned[c[1]] += add; ned[c[tot]] += add; for(int i = 2 ; i <= tot ; ++i) { ans += abs(ned[c[i - 1]]); ned[c[i]] += ned[c[i - 1]]; ned[c[i - 1]] = 0; } for(int i = tot - 1 ; i >= 1 ; --i) { ans += abs(ned[c[i + 1]]); ned[c[i]] += ned[c[i + 1]]; } out(ans + abs(add));enter; } void Process() { find_circle(1); for(int i = 1 ; i <= N ; ++i) { rec[col[i]]++; } int p = st; while(1) { c[++tot] = p; if(p == ed) break; p = fa[p]; } if(tot % 2 == 0) { if(rec[0] != rec[1]) {puts("-1");return;} EvenCircle(); } else { if((rec[0] ^ rec[1]) & 1) {puts("-1");return;} OddCircle(); } } void Solve() { srand(time(0)); read(N);read(M); int a,b; for(int i = 1 ; i <= M ; ++i) { read(a);read(b); add(a,b);add(b,a); } if(N & 1) {puts("-1");return;} if(M == N - 1) { dfs(1); if(dp[1][0] || dp[1][1]) {puts("-1");return;} out(ans);enter; } else Process(); } int main() { #ifdef ivorysi freopen("f1.in","r",stdin); #endif Solve(); return 0; }