Submission #2561077

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Source Code Expand

N, M = input().split()
N = int(N)
M = int(M)

pList = input().split()
pairList = []

indexList = [0 for _ in range(N+1)]
groupNum = 1
for i in range(M):
    thisPair = input().split()
    p1 = int(thisPair[0])
    p2 = int(thisPair[1])
    if indexList[p1] == 0 and indexList[p2] == 0:
        indexList[p1] = groupNum
        indexList[p2] = groupNum
        groupNum += 1
    elif indexList[p1] == 0 and indexList[p2] != 0:
        indexList[p1] = indexList[p2]
    elif indexList[p1] != 0 and indexList[p2] == 0:
        indexList[p2] = indexList[p1]
    else:
        unifiedGroup = indexList[p1]
        for i in range(len(indexList)):
            if indexList[i] == unifiedGroup:
                indexList[i] = indexList[p2]
    # print(indexList)


groupMap = {}
for i in range(len(indexList)):
    if str(indexList[i]) in groupMap.keys():
        groupMap[str(indexList[i])].append(i)
    else:
        groupMap[str(indexList[i])] = [i]
# print(pList)
# print(groupMap)
# print(indexList)
res = 0
for i in range(1,len(pList)+1):
    if i == int(pList[i-1]):
        # print(i)
        res += 1
    else:
        groupName = str(indexList[i])
        if i in groupMap[groupName] and int(pList[i-1]) in groupMap[groupName]:
            # print(i, 'a')
            res += 1
print(res)

Submission Info

Judge Result