平时一测

第一题：SPFA，最难的还是读入，一般读入接上一行的 ;

#include<algorithm>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<queue>
using namespace std;


const int M = 4005;
int S, T, p, h[M], tot, dis[M];
bool inq[M];
struct edge{int v, nxt;}G[M];
void add(int u, int v){
    G[++tot].v = v; G[tot].nxt = h[u]; h[u] = tot;
}
inline int rec(int z){
    int t = (z + 19) / 20 + z;
    while(t - (t + 19) / 20 < z)t++;
    return t;
}
void spfa(){
    queue <int> Q;
    memset(dis, 127, sizeof(dis));
    memset(inq, 0, sizeof(inq));
    Q.push(T);
    
    dis[T] = p;
    inq[T] = 1;
    
    while(!Q.empty()){
        int u = Q.front(); Q.pop(); inq[u] = 0;
        for(int i = h[u]; i; i = G[i].nxt){
            int v = G[i].v;
            int w = u >= 100 ? rec(dis[u]) : dis[u] + 1;
            if(w < dis[v]){
                dis[v] = w;
                if(!inq[v])Q.push(v), inq[v] = 0;
            }
        }
    }
}


inline void get(char a, char b){
    int u, v;
    if(a <='Z' && a >='A')
        u = a-'A' + 100;
    else u = a-'a';
    
    if(b <='Z' && b >='A')
        v = b-'A' + 100;
    else v = b-'a';
    add(v, u); add(u, v);
}
void init(char a, char b){
    int u, v;
    if(a <='Z' && a >='A')
        u = a-'A' + 100;
    else u = a-'a';
    
    if(b <='Z' && b >='A')
        v = b-'A' + 100;
    else v = b-'a';
    S = u, T = v;
}

void cls(){
    memset(h, 0, sizeof(h));
    tot = 0;
}
int main(){
    freopen("toll.in","r",stdin);
    freopen("toll.out","w",stdout);
    int n, idc = 0;
    while(scanf("%d", &n) == 1 && n != -1){
        idc++;
        cls();
        char a, b, s, t;
        for(int i = 1; i <= n; i++){
            scanf("
%c %c", &a, &b);
        //    printf("%c %c
", a, b);
            get(a, b);
        }
        scanf("%d %c %c", &p, &s, &t);
        //printf("start %c %c
",s, t);
        init(s, t);
        spfa();
        printf("Case %d: %d
", idc,dis[S]);
    }    
}

第二题：ＬＩＳ即为答案，一个逆序对一条边，只有ＬＩＳ里面没有边，应该多想一下，这道题很简单，但我方向完全偏了；

第三题：搜索＋剪枝，所有数据都很小，所以可以实际跑的很快，本来想状压没搞出来；

#include<algorithm>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<queue>
using namespace std;
#define For(a, b, c) for(int a = b; a <= c; a++)
const int M = (1 << 14) + 1;
int visr[M], visg[M], visw[M], ans, n;
struct POINT{int sr,sg,kr,kg,kw;}d[15];
inline bool better(int s, int rr, int gg, int ww){
    int nw = visw[s], tt = visr[s] - rr;
    if(tt > 0) ww -= tt;
    else nw += tt;
    if(ww + gg < visg[s] + nw || ( rr == visr[s] && gg == visg[s] && ww == visw[s]) )return 0; 
    visr[s] = max(visr[s], rr); 
    visw[s] = max(visw[s], ww); 
    visg[s] = max(visg[s], gg); 
    return 1;
} 


void dfs(int dep, int sta, int rr, int gg, int ww){
    //printf("%d %d %d %d
",sta, rr,gg,ww);
    ans = max(ans, rr + gg + ww);
    if(dep == n + 1)return ;
    if(!better(sta, rr, gg, ww))return;
    for(int i = 1; i <= n; i++)
        if(!(sta & (1 << (i - 1)))){
            if(d[i].sr <= rr + ww){        
                int nr = rr >= d[i].sr ? rr - d[i].sr : 0;
                int nw = rr >= d[i].sr ? ww : ww - (d[i].sr - rr);    
                int ng = gg >= d[i].sg ? gg - d[i].sg : 0;
                nw = gg >= d[i].sg ? nw : nw - (d[i].sg - gg);
                if(nw < 0)continue;
                dfs(dep + 1, sta | (1 << (i - 1)), nr + d[i].kr, ng + d[i].kg, 
                nw + d[i].kw);
            }
        }
            
}

int main(){
    //freopen("room.in","r",stdin);
    //freopen("room.out","w",stdout);
    int k0, k1, k2;
    scanf("%d", &n);
    memset(visg, -1, sizeof(visg));
    memset(visr, -1, sizeof(visr));
    memset(visw, -1, sizeof(visw));
    For(i, 1, n) scanf("%d", &d[i].sr);
    For(i, 1, n) scanf("%d", &d[i].sg);
    For(i, 1, n) scanf("%d", &d[i].kr);
    For(i, 1, n) scanf("%d", &d[i].kg);
    For(i, 1, n) scanf("%d", &d[i].kw);
/*    For(i, 1, n)
        d[i].tot = d[i].kr + d[i].kg + d[i].kw;
*/    scanf("%d%d%d", &k0, &k1, &k2); //0 red 1 green 2 white

    ans = k0 + k1 + k2;
    dfs(1, 0, k0, k1, k2);
    printf("%d
",ans);
}

今天题应该是很水的，然而考的不好，思维僵硬了；