sysy-data/hidden_functional_c/sy/10_DFS.sy

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#include "sylib.h"
int quick_read(){
int ch = getch(); int x = 0, f = 0;
while (ch < 48 || ch > 57){
if (ch == 45) f = 1;
ch = getch();
}
while (ch >= 48 && ch <=57){
x = x * 10 + ch - 48;
ch = getch();
}
if (f) return -x;
else return x;
}
int n, m;
#define maxn 1005
#define maxm 5005
int to[maxm], next[maxm], head[maxn], cnt = 0;
void add_edge(int from, int To){
to[cnt] = To;
next[cnt] = head[from];
head[from] = cnt;
cnt = cnt + 1;
to[cnt] = from;
next[cnt] = head[To];
head[To] = cnt;
cnt = cnt + 1;
}
void init(){
int i = 0;
while (i < maxn){
head[i] = -1;
i = i + 1;
}
}
int vis[maxn];
void clear(){
int i = 1;
while (i <= n){
vis[i] = 0;
i = i + 1;
}
}
int same(int x, int tar){
vis[x] = 1;
if (x == tar) return 1;
int i = head[x];
while (i != -1){
int y = to[i];
if (!vis[y] && same(y,tar))
return 1;
i = next[i];
}
return 0;
}
int main(){
n = quick_read(); m = quick_read();
init();
while (m){
int ch = getch();
while (ch != 81 && ch != 85){
ch = getch();
}
if (ch == 81){ // query
int x = quick_read(), y = quick_read();
clear();
putint(same(x, y));
putch(10);
}else{ // union
int x = quick_read(), y = quick_read();
add_edge(x, y);
}
m = m - 1;
}
return 0;
}