2012 icpc 成都赛区的一题, 被坑了..唉往事不堪重提
#include <cstdio>#include <cstring>#include <queue>#define MAXVERTEX803#define MAXARC170000#define INF0x7fffffffusing namespace std;struct Edge{int v, val, next;}edge[MAXARC];int e_cnt;char map[MAXVERTEX][MAXVERTEX];int head[MAXVERTEX], dis[MAXVERTEX], gap[MAXVERTEX], cur[MAXVERTEX], pre[MAXVERTEX];void insert_arc(int u, int v, int w){edge[e_cnt].v = v; edge[e_cnt].val = w;edge[e_cnt].next = head[u];head[u] = e_cnt ++;swap(u, v);edge[e_cnt].v = v; edge[e_cnt].val = 0;edge[e_cnt].next = head[u];head[u] = e_cnt ++;}void bfs(int des, int NV){int u, v;queue<int> q;memset(dis, -1, sizeof(dis));memset(gap, 0, sizeof(gap));q.push(des);dis[des] = 0;gap[0] = 1;while( !q.empty() ) {u = q.front(); q.pop();for(int i = head[u]; i != -1; i = edge[i].next) {v = edge[i].v;if( edge[i].val || dis[v] != -1 )continue;q.push(v);dis[v] = dis[u]+1;gap[dis[v]] ++;}}}int i_sap(int src, int des, int VN){int u(src), v, min_dis, max_flow(0), path_flow(INF);bfs(des,VN);pre[u] = u;for(int i = 0; i <= VN; i ++)cur[i] = head[i];while( dis[src] < VN ) {loop:for(int &i = cur[u]; i != -1; i = edge[i].next) {v = edge[i].v;if( !edge[i].val || dis[u] != dis[v]+1 )continue;pre[v] = u;path_flow = min(path_flow, edge[i].val);u = v;if( v == des ) {for(u = pre[u]; v != src; v = u, u = pre[u]) {edge[cur[u]].val -= path_flow;edge[cur[u]^1].val += path_flow;}max_flow += path_flow; path_flow = INF;}goto loop;}min_dis = VN;for(int i = head[u]; i != -1; i = edge[i].next) {v = edge[i].v;if( edge[i].val && min_dis > dis[v] ) {cur[u] = i;min_dis = dis[v];}}gap[dis[u]] --;if( !gap[dis[u]] )break;dis[u] = min_dis+1;gap[dis[u]] ++; u = pre[u];}return max_flow;}int main(int argc, char const *argv[]){int vertex, fc, dc, v, src, des, VN, base;register int i, j;while( ~scanf("%d %d %d", &vertex, &fc, &dc) ) {src = 2*vertex+fc+dc+1;des = src+1;VN = des;e_cnt = 0;memset(head, -1, sizeof(head));for(i = 1; i <= fc; i ++) {scanf("%d", &v);insert_arc(src, i, v);}for( i = 1; i <= dc; i ++) {scanf("%d", &v); insert_arc(fc+i, des, v);}base = fc+dc;for( i = 0; i < vertex; i ++)scanf("%s", map[i]);for( i = 1; i <= vertex; i ++) {insert_arc(base+i, base+i+vertex, 1);for( j = 1; j <= fc; j ++) {if( 'Y' == map[i-1][j-1] ) insert_arc(j, base+i, 1);}}for( i = 0; i < vertex; i ++)scanf("%s", map[i]);base += vertex;for( i = 1; i <= vertex; i ++) {for( j = 1; j <= dc; j ++) {if( 'Y' == map[i-1][j-1] )insert_arc(base+i, j+fc, 1);}}printf("%d\n", i_sap(src, des, VN));}return 0;}
