soj 4526 不重叠最短路条数

分析：记录路径，每一次最短路都删去边，最后最短路变长了就停止。

/**********************jibancanyang************************** *Author*        :jibancanyang *Created Time*  : 一  5/30 17:18:48 2016**Problem**:**Analyse**:**Get**:**Code**:***********************[e-mail]**********************/#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>#include <vector>#include <queue>#include <set>#include <map>#include <string>#include <cmath>#include <cstdlib>#include <ctime>#include <stack>using namespace std;typedef pair<int, int> pii;typedef long long ll;typedef unsigned long long ull;vector<int> vi;#define pr(x) cout << #x << ": " << x << "  " #define pl(x) cout << #x << ": " << x << endl;#define pri(a) printf("%d\n",(a));#define xx first#define yy second#define sa(n) scanf("%d", &(n))#define sal(n) scanf("%lld", &(n))#define sai(n) scanf("%I64d", &(n))#define vep(c) for(decltype((c).begin() ) it = (c).begin(); it != (c).end(); it++) const int mod = int(1e9) + 7, INF = 0x3f3f3f3f;const int maxn = 1e3 + 13;struct node {    int to, cost;    node (int A, int B): to(A), cost(B) {}};int vis[maxn][maxn];int logs[maxn][maxn];vector<node> G[maxn];int d[maxn], pre[maxn],s, e, n, m;int dijkstra(void) {    fill(d + 1, d + n + 1, INF);    priority_queue<pii, vector<pii>, greater<pii> > que;    que.push(pii(0, s));    d[s] = 0;    pre[s] = -1;    while (!que.empty()) {        pii cur = que.top(); que.pop();        if (cur.yy == e) return cur.xx;         if (cur.xx > d[cur.yy]) continue;        for (int i = 0; i < (int)G[cur.yy].size(); i++) {            node nxt = G[cur.yy][i];            if (vis[cur.yy][nxt.to] <= 0) continue;            if (d[nxt.to] > cur.xx + nxt.cost) {                d[nxt.to] = cur.xx + nxt.cost;                que.push(pii(d[nxt.to], nxt.to));                pre[nxt.to] = cur.yy;            }        }    }    return -1;}int main(void){#ifdef LOCAL    freopen("/Users/zhaoyang/in.txt", "r", stdin);    //freopen("/Users/zhaoyang/out.txt", "w", stdout);#endif    int T; sa(T);    while (T--) {        memset(vis, 0, sizeof(vis));        sa(n), sa(m);        for (int i = 1; i <= n; i++) fill(logs[i] + 1, logs[i] + n + 1, INF);        for (int i = 0; i < m; i++) {            int x, y, z;            sa(x), sa(y), sa(z);            if (z < logs[x][y]) {vis[x][y] = 1; logs[x][y] = z;}            else if (z == logs[x][y]) vis[x][y]++;            else continue;            G[x].push_back(node(y, z));        }        sa(s), sa(e);        int mins = dijkstra(), ans = 0;        if (mins == -1) puts("0");        else {            while (true) {                ans++;                int x = e;                while (pre[x] != -1) {                //    pr(pre[x]), pl(x);                    vis[pre[x]][x]--;                    x = pre[x];                }                x = dijkstra();                if (x != mins) break;            }            pri(ans);        }    }    return 0;}